View source for Rationalism

{{Short description|Epistemological view centered on reason}}
{{About|the philosophical concept|the 21st-century movement|rationalist community|other uses}}
{{Distinguish|rationality|Rationalization (disambiguation){{!}}rationalization}}

{{Multiple image|caption_align=center
| total_width       = 300
<!--image 1-->
| image2            = Frans Hals - Portret van René Descartes.jpg
| width2            = 800
| height2           = 828
| alt2              =
| link2             =
| caption2          = [[René Descartes]]
<!--image 2-->
| image3            = Spinoza.jpg
| width3            = 700
| height3           = 828
| alt3              =
| link3             =
| caption3          = [[Baruch Spinoza]]
<!--image 3-->
| image4            = Christoph Bernhard Francke - Bildnis des Philosophen Leibniz (ca. 1695).jpg
| width4            = 700
| height4           = 828
| alt4              =
| link4             =
| caption4          = [[Gottfried Wilhelm Leibniz|Gottfried Leibniz]]
}}

{{Epistemology sidebar}}

In [[philosophy]], '''rationalism''' is the [[Epistemology|epistemological]] view that "regards [[reason]] as the chief source and test of knowledge"<ref name="Encyclopædia Britannica: Rationalism">{{cite web|url=http://www.britannica.com/EBchecked/topic/492034/rationalism|title=Rationalism|date=28 May 2023|publisher=[[Encyclopædia Britannica|Britannica.com]]|access-date=22 May 2013|archive-date=18 May 2015|archive-url=https://web.archive.org/web/20150518105808/https://www.britannica.com/EBchecked/topic/492034/rationalism|url-status=live}}</ref> or "the position that reason has precedence over other ways of acquiring knowledge",<ref name="Audi 902">{{cite book |last=Audi |first=Robert |author-link= |date=2015 |title=The Cambridge Dictionary of Philosophy |url=https://books.google.com/books?id=ISBN1107015057 |location=Cambridge |publisher=Cambridge University Press |page=902 |isbn=978-1107015050}}</ref> often in contrast to other possible sources of knowledge such as [[religious faith|faith]],  tradition, or [[sensory experience]]. More formally, rationalism is defined as a [[methodology]] or a [[theory]] "in which the criterion of [[truth]] is not sensory but intellectual and [[Deductive reasoning|deductive]]".<ref name="Bourke 263">Bourke, Vernon J., "Rationalism", p. 263 in Runes (1962).</ref>

In a major philosophical debate during the [[Age of Enlightenment|Enlightenment]],<ref name= essay >[[John Locke]] (1690), [[An Essay Concerning Human Understanding]]</ref> rationalism (sometimes here equated with [[innatism]]) was opposed to [[empiricism]]. On the one hand, rationalists like [[René Descartes]] emphasized that knowledge is primarily innate and the intellect, the inner [[Faculty (disambiguation)#Biology|faculty]] of the human mind, can therefore directly grasp or derive [[Logical truth|logical truths]]; on the other hand, empiricists like [[John Locke]] emphasized that knowledge is not primarily innate and is best gained by careful observation of the physical world outside the mind, namely through sensory experiences. Rationalists asserted that certain principles exist in [[logic]], [[mathematics]], [[ethics]], and [[metaphysics]] that are so fundamentally true that denying them causes one to fall into contradiction. The rationalists had such a high confidence in reason that empirical proof and physical evidence were regarded as unnecessary to ascertain certain truths{{snd}}in other words, "there are significant ways in which our concepts and knowledge are gained independently of sense experience".<ref name="Rationalism vs. Empiricism">''Stanford Encyclopedia of Philosophy'', [http://plato.stanford.edu/entries/rationalism-empiricism/ "Rationalism vs. Empiricism"] {{Webarchive|url=https://web.archive.org/web/20180929143915/http://plato.stanford.edu/entries/rationalism-empiricism/ |date=2018-09-29 }} First published August 19, 2004; substantive revision March 31, 2013 cited on May 20, 2013.</ref>

Different degrees of emphasis on this method or theory lead to a range of rationalist standpoints, from the moderate position "that reason has precedence over other ways of acquiring knowledge" to the more extreme position that reason is "the unique path to knowledge".<ref name="Audi 902"/> Given a [[pre-modern]] understanding of reason, rationalism is identical to [[philosophy]], the [[Socrates|Socratic]] life of inquiry, or the zetetic ([[Skepticism|skeptical]]) clear interpretation of authority (open to the underlying or essential cause of things as they appear to our sense of certainty).

==Background<!--'Continental rationalism' and 'Continental Rationalism' redirect here-->==

Rationalism has a philosophical history dating from [[Ancient philosophy|antiquity]]. The [[analytic philosophy|analytical]] nature of much of philosophical enquiry, the awareness of apparently [[A priori knowledge|a priori]] domains of knowledge such as mathematics, combined with the emphasis of obtaining knowledge through the use of rational faculties (commonly rejecting, for example, direct [[revelation]]) have made rationalist themes very prevalent in the [[history of philosophy]].

Since the Enlightenment, rationalism is usually associated with the introduction of mathematical methods into philosophy as seen in the works of [[Descartes]], [[Gottfried Wilhelm Leibniz|Leibniz]], and [[Spinoza]].<ref name="Bourke 263"/> This is commonly called '''continental rationalism'''<!--boldface per WP:R#PLA-->, because it was predominant in the continental schools of Europe, whereas in Britain [[empiricism]] dominated.

Even then, the distinction between rationalists and empiricists was drawn at a later period and would not have been recognized by the philosophers involved. Also, the distinction between the two philosophies is not as clear-cut as is sometimes suggested; for example, Descartes and Locke have similar views about the nature of human ideas.<ref name="Rationalism vs. Empiricism"/>

Proponents of some varieties of rationalism argue that, starting with foundational basic principles, like the axioms of [[geometry]], one could [[deductive reasoning|deductively]] derive the rest of all possible knowledge. Notable philosophers who held this view most clearly were [[Baruch Spinoza]] and [[Gottfried Leibniz]], whose attempts to grapple with the epistemological and metaphysical problems raised by Descartes led to a development of the fundamental approach of rationalism. Both Spinoza and Leibniz asserted that, ''in principle'', all knowledge, including scientific knowledge, could be gained through the use of reason alone, though they both observed that this was not possible ''in practice'' for human beings except in specific areas such as [[mathematics]]. On the other hand, Leibniz admitted in his book ''[[Monadology]]'' that "we are all mere [[Empirics]] in three fourths of our actions."<ref name="Audi 771">Audi, Robert, The Cambridge Dictionary of Philosophy, Cambridge University Press, Cambridge, UK, 1995. 2nd edition, 1999, p. 771.</ref>

===Political usage===
In [[politics]], rationalism, since the [[Age of Enlightenment|Enlightenment]], historically emphasized a "politics of reason" centered upon [[rationality]], [[deontology]], [[utilitarianism]], [[secularism]], and [[irreligion]]<ref>Oakeshott, Michael, "[http://faculty.isi.org/catalog/resource/view/id/678 Rationalism in Politics]", ''The Cambridge Journal'' 1947, vol. 1 {{Webarchive|url=https://web.archive.org/web/20180913150754/https://faculty.isi.org/catalog/resource/view/id/678 |date=2018-09-13 }}. Retrieved 2013-01-13.</ref>{{snd}}the latter aspect's [[antitheism]] was later softened by the adoption of pluralistic reasoning methods practicable regardless of religious or irreligious ideology.<ref>[http://usj.sagepub.com/content/43/5-6/863.abstract Boyd, Richard, "The Value of Civility?", ''Urban Studies Journal'', May 2006, vol. 43 (no. 5–6), pp. 863–878] {{Webarchive|url=https://web.archive.org/web/20120401135541/http://usj.sagepub.com/content/43/5-6/863.abstract |date=2012-04-01 }}. Retrieved 2013-01-13.</ref><ref>[https://www.factcheck.org/spindetectors/about/ ''FactCheck.org Mission Statement'', January 2020] {{Webarchive|url=https://web.archive.org/web/20191102201015/https://www.factcheck.org/spindetectors/about/ |date=2019-11-02 }}. Retrieved 2020-01-01.</ref> In this regard, the philosopher [[John Cottingham]]<ref>Cottingham, John. 1984. ''Rationalism''. Paladi/Granada.</ref> noted how rationalism, a [[methodology]], became socially conflated with [[atheism]], a [[worldview]]:
{{quote|In the past, particularly in the 17th and 18th centuries, the term 'rationalist' was often used to refer to free thinkers of an anti-clerical and anti-religious outlook, and for a time the word acquired a distinctly pejorative force (thus in 1670 Sanderson spoke disparagingly of 'a mere rationalist, that is to say in plain English an atheist of the late edition...'). The use of the label 'rationalist' to characterize a world outlook which has no place for the supernatural is becoming less popular today; terms like '[[secular humanist|humanist]]' or '[[materialism|materialist]]' seem largely to have taken its place. But the old usage still survives.}}

==Philosophical usage==
Rationalism is often contrasted with [[empiricism]]. Taken very broadly, these views are not mutually exclusive, since{{snd}}on some definitions{{snd}}a philosopher can be both rationalist and empiricist.<ref name="Lacey 286">Lacey, A.R. (1996), ''A Dictionary of Philosophy'', 1st edition, Routledge and Kegan Paul, 1976. 2nd edition, 1986. 3rd edition, Routledge, London, 1996. p. 286</ref><ref name="Audi 902"/> Taken to extremes, the empiricist view holds that all ideas come to us [[A priori and a posteriori|''a posteriori'']], that is to say, through experience; either through the external senses or through such inner sensations as pain and gratification. The empiricist essentially believes that knowledge is based on or derived directly from experience. The rationalist believes we come to knowledge [[A priori and a posteriori|''a priori'']]{{snd}}through the use of logic{{snd}} and is thus independent of sensory experience. In other words, as [[Galen Strawson]] once wrote, "you can see that it is true just lying on your couch. You don't have to get up off your couch and go outside and examine the way things are in the physical world. You don't have to do any science."<ref>Sommers (2003), p. 15.</ref>

Between both philosophies, the issue at hand is the fundamental source of human knowledge and the proper techniques for verifying what we think we know. Whereas both philosophies are under the umbrella of [[epistemology]], their argument lies in the understanding of the warrant, which is under the wider epistemic umbrella of the [[theory of justification]]. Part of [[epistemology]], this theory attempts to understand the justification of [[propositions]] and [[belief]]s. Epistemologists are concerned with various epistemic features of belief, which include the ideas of [[Formal proof|justification]], warrant, [[rationality]], and [[probability]]. Of these four terms, the term that has been most widely used and discussed by the early 21st century is "warrant". Loosely speaking, justification is the reason that someone (probably) holds a belief.

If ''A'' makes a claim and then ''B'' casts doubt on it, ''A''{{'}}s next move would normally be to provide justification for the claim. The precise method one uses to provide justification is where the lines are drawn between rationalism and empiricism (among other philosophical views). Much of the debate in these fields are focused on [[Philosophical analysis|analyzing]] the nature of knowledge and how it relates to connected notions such as [[truth]], [[belief]], and [[Formal proof|justification]].

At its core, rationalism consists of three basic claims. For people to consider themselves rationalists, they must adopt at least one of these three claims: the intuition/deduction thesis, the innate knowledge thesis, or the innate concept thesis. In addition, a rationalist can choose to adopt the claim of Indispensability of Reason and or the claim of Superiority of Reason, although one can be a rationalist without adopting either thesis.{{cn|date=December 2021}}

'''The indispensability of reason thesis''': "The knowledge we gain in subject area, ''S'', by intuition and deduction, as well as the ideas and instances of knowledge in ''S'' that are innate to us, could not have been gained by us through sense experience."<ref name="Encyclopædia Britannica: Rationalism">{{cite web|url=http://www.britannica.com/EBchecked/topic/492034/rationalism|title=Rationalism|date=28 May 2023|publisher=[[Encyclopædia Britannica|Britannica.com]]|access-date=22 May 2013|archive-date=18 May 2015|archive-url=https://web.archive.org/web/20150518105808/https://www.britannica.com/EBchecked/topic/492034/rationalism|url-status=live}}</ref> In short, this thesis claims that experience cannot provide what we gain from reason.

'''The superiority of reason thesis''': '"The knowledge we gain in subject area ''S'' by intuition and deduction or have innately is superior to any knowledge gained by sense experience".<ref name="Encyclopædia Britannica: Rationalism"/> In other words, this thesis claims reason is superior to experience as a source for knowledge.

Rationalists often adopt similar stances on other aspects of philosophy. Most rationalists reject skepticism for the areas of knowledge they claim are knowable [[A priori and a posteriori|''a priori'']]. When you claim some truths are innately known to us, one must reject skepticism in relation to those truths. Especially for rationalists who adopt the Intuition/Deduction thesis, the idea of epistemic [[foundationalism]] tends to crop up. This is the view that we know some truths without basing our belief in them on any others and that we then use this foundational knowledge to know more truths.<ref name="Encyclopædia Britannica: Rationalism"/>

===Intuition/deduction thesis===
{{Main|Intuition (philosophy)|Deductive reasoning}}

{{Blockquote|text=''"Some propositions in a particular subject area, S, are knowable by us by intuition alone; still others are knowable by being deduced from intuited propositions."''<ref name="The Intuition/Deduction Thesis">Stanford Encyclopedia of Philosophy, [http://plato.stanford.edu/entries/rationalism-empiricism/#2 The Intuition/Deduction Thesis] {{Webarchive|url=https://web.archive.org/web/20180929143915/http://plato.stanford.edu/entries/rationalism-empiricism/#2 |date=2018-09-29 }} First published August 19, 2004; substantive revision March 31, 2013 cited on May 20, 2013.</ref>}}

Generally speaking, intuition is [[A priori and a posteriori|''a priori'']] knowledge or experiential belief characterized by its immediacy; a form of rational insight. We simply "see" something in such a way as to give us a warranted belief. Beyond that, the nature of intuition is hotly debated. In the same way, generally speaking, deduction is the process of [[reasoning]] from one or more general [[premise]]s to reach a logically certain conclusion. Using valid [[argument]]s, we can deduce from intuited premises.

For example, when we combine both concepts, we can intuit that the number three is prime and that it is greater than two. We then deduce from this knowledge that there is a prime number greater than two. Thus, it can be said that intuition and deduction combined to provide us with ''a priori'' knowledge{{snd}}we gained this knowledge independently of sense experience.

To argue in favor of this thesis, [[Gottfried Wilhelm Leibniz]], a prominent German philosopher, says,

{{Blockquote|text=The senses, although they are necessary for all our actual knowledge, are not sufficient to give us the whole of it, since the senses never give anything but instances, that is to say particular or individual truths. Now all the instances which confirm a general truth, however numerous they may be, are not sufficient to establish the universal necessity of this same truth, for it does not follow that what happened before will happen in the same way again. … From which it appears that necessary truths, such as we find in pure mathematics, and particularly in arithmetic and geometry, must have principles whose proof does not depend on instances, nor consequently on the testimony of the senses, although without the senses it would never have occurred to us to think of them…<ref>Gottfried Wilhelm Leibniz, 1704, ''New Essays on Human Understanding'', Preface, pp. 150–151.</ref>}}

Empiricists such as [[David Hume]] have been willing to accept this thesis for describing the relationships among our own concepts.<ref name="The Intuition/Deduction Thesis"/> In this sense, empiricists argue that we are allowed to intuit and deduce truths from knowledge that has been obtained [[A priori and a posteriori|''a posteriori'']].

By injecting different subjects into the Intuition/Deduction thesis, we are able to generate different arguments. Most rationalists agree [[mathematics]] is knowable by applying the intuition and deduction. Some go further to include [[Ethics|ethical truths]] into the category of things knowable by intuition and deduction. Furthermore, some rationalists also claim [[metaphysics]] is knowable in this thesis. Naturally, the more subjects the rationalists claim to be knowable by the Intuition/Deduction thesis, the more certain they are of their warranted beliefs, and the more strictly they adhere to the infallibility of intuition, the more controversial their truths or claims and the more radical their rationalism.<ref name="The Intuition/Deduction Thesis"/>

In addition to different subjects, rationalists sometimes vary the strength of their claims by adjusting their understanding of the warrant. Some rationalists understand warranted beliefs to be beyond even the slightest doubt; others are more conservative and understand the warrant to be belief beyond a reasonable doubt.

Rationalists also have different understanding and claims involving the connection between intuition and truth. Some rationalists claim that intuition is infallible and that anything we intuit to be true is as such. More contemporary rationalists accept that intuition is not always a source of certain knowledge{{snd}}thus allowing for the possibility of a deceiver who might cause the rationalist to intuit a false proposition in the same way a third party could cause the rationalist to have perceptions of [[nonexistent object]]s.

===Innate knowledge thesis===
{{Blockquote|text=''"We have knowledge of some truths in a particular subject area, S, as part of our rational nature."''<ref name="The Innate Knowledge Thesis">Stanford Encyclopedia of Philosophy, [http://plato.stanford.edu/entries/rationalism-empiricism/#3 The Innate Knowledge Thesis] {{Webarchive|url=https://web.archive.org/web/20180929143915/http://plato.stanford.edu/entries/rationalism-empiricism/#3 |date=2018-09-29 }} First published August 19, 2004; substantive revision March 31, 2013 cited on May 20, 2013.</ref>}}

The Innate Knowledge thesis is similar to the Intuition/Deduction thesis in the regard that both theses claim [[knowledge]] is gained [[A priori and a posteriori|''a priori'']]. The two theses go their separate ways when describing how that knowledge is gained. As the name, and the rationale, suggests, the Innate Knowledge thesis claims knowledge is simply part of our rational nature. Experiences can trigger a process that allows this knowledge to come into our consciousness, but the experiences do not provide us with the knowledge itself. The knowledge has been with us since the beginning and the experience simply brought into focus, in the same way a photographer can bring the background of a picture into focus by changing the aperture of the lens. The background was always there, just not in focus.

This thesis targets a problem with the nature of inquiry originally postulated by [[Plato]] in ''[[Meno]]''. Here, Plato asks about inquiry; how do we gain knowledge of a theorem in geometry? We inquire into the matter. Yet, knowledge by inquiry seems impossible.<ref>Meno, 80d–e.</ref> In other words, "If we already have the knowledge, there is no place for inquiry. If we lack the knowledge, we don't know what we are seeking and cannot recognize it when we find it. Either way we cannot gain knowledge of the theorem by inquiry. Yet, we do know some theorems."<ref name="The Innate Knowledge Thesis"/> The Innate Knowledge thesis offers a solution to this [[paradox]]. By claiming that knowledge is already with us, either [[Consciousness|consciously]] or [[Unconscious mind|unconsciously]], a rationalist claims we don't really learn things in the traditional usage of the word, but rather that we simply use words we know.

===Innate concept thesis===
{{Blockquote|text=''"We have some of the concepts we employ in a particular subject area, S, as part of our rational nature."''<ref name="The Innate Concept Thesis">Stanford Encyclopedia of Philosophy, [http://plato.stanford.edu/entries/rationalism-empiricism/#4 The Innate Concept Thesis] {{Webarchive|url=https://web.archive.org/web/20180929143915/http://plato.stanford.edu/entries/rationalism-empiricism/#4 |date=2018-09-29 }} First published August 19, 2004; substantive revision March 31, 2013 cited on May 20, 2013.</ref>}}

Similar to the Innate Knowledge thesis, the Innate Concept thesis suggests that some concepts are simply part of our rational nature. These concepts are [[A priori and a posteriori|''a priori'']] in nature and sense experience is irrelevant to determining the nature of these concepts (though, sense experience can help bring the concepts to our [[Consciousness|conscious mind]]).

In his book ''[[Meditations on First Philosophy]]'',<ref>{{cite book |url= https://archive.org/details/descartesmeditat00rend |url-access= registration |editor1-first= J. |editor1-last=Cottingham |year=1996 |orig-year= 1986 |edition= revised |publisher= Cambridge University Press |isbn= 978-0521558181 |title= Meditations on First Philosophy With Selections from the Objections and Replies }}{{snd}}The original ''Meditations'', translated, in its entirety.</ref> [[René Descartes]] postulates three classifications for our [[idea]]s when he says, "Among my ideas, some appear to be innate, some to be adventitious, and others to have been invented by me. My understanding of what a thing is, what truth is, and what thought is, seems to derive simply from my own nature. But my hearing a noise, as I do now, or seeing the sun, or feeling the fire, comes from things which are located outside me, or so I have hitherto judged. Lastly, [[Siren (mythology)|sirens]], [[hippogriff]]s and the like are my own invention."<ref>René Descartes AT VII 37–38; CSM II 26.</ref>

Adventitious ideas are those concepts that we gain through sense experiences, ideas such as the sensation of heat, because they originate from outside sources; transmitting their own likeness rather than something else and something you simply cannot [[Will (philosophy)|will]] away. Ideas invented by us, such as those found in [[mythology]], [[legend]]s and [[fairy tale]]s, are created by us from other ideas we possess. Lastly, innate ideas, such as our ideas of [[perfection]], are those ideas we have as a result of mental processes that are beyond what experience can directly or indirectly provide.

[[Gottfried Wilhelm Leibniz]] defends the idea of innate concepts by suggesting the mind plays a role in determining the nature of concepts, to explain this, he likens the mind to a block of marble in the ''[[New Essays on Human Understanding]]'',

{{Blockquote|text=This is why I have taken as an illustration a block of veined marble, rather than a wholly uniform block or blank tablets, that is to say what is called ''[[tabula rasa]]'' in the language of the philosophers. For if the soul were like those blank tablets, truths would be in us in the same way as the figure of Hercules is in a block of marble, when the marble is completely indifferent whether it receives this or some other figure. But if there were veins in the stone which marked out the figure of Hercules rather than other figures, this stone would be more determined thereto, and Hercules would be as it were in some manner innate in it, although labour would be needed to uncover the veins, and to clear them by polishing, and by cutting away what prevents them from appearing. It is in this way that ideas and truths are innate in us, like natural inclinations and dispositions, natural habits or potentialities, and not like activities, although these potentialities are always accompanied by some activities which correspond to them, though they are often imperceptible."<ref>Gottfried Wilhelm Leibniz, 1704, ''New Essays on Human Understanding'', Preface, p. 153.</ref>}}

Some philosophers, such as [[John Locke]] (who is considered one of the most influential thinkers of the [[Age of Enlightenment|Enlightenment]] and an [[Empiricism|empiricist]]), argue that the Innate Knowledge thesis and the Innate Concept thesis are the same.<ref>Locke, ''Concerning Human Understanding'', Book I, Ch. III, Par. 20.</ref> Other philosophers, such as [[Peter Carruthers (philosopher)|Peter Carruthers]], argue that the two theses are distinct from one another. As with the other theses covered under the umbrella of rationalism, the more types and greater number of concepts a philosopher claims to be innate, the more controversial and radical their position; "the more a concept seems removed from experience and the mental operations we can perform on experience the more plausibly it may be claimed to be innate. Since we do not experience perfect triangles but do experience pains, our concept of the former is a more promising candidate for being innate than our concept of the latter.<ref name="The Innate Concept Thesis"/>

==History==
===Rationalist philosophy in Western antiquity===
[[File:Pythagoras with tablet of ratios.jpg|thumb|Detail of Pythagoras with a tablet of ratios, numbers sacred to the Pythagoreans, from ''[[The School of Athens]]'' by [[Raphael]]. [[Vatican Palace]], [[Vatican City]]]]
Although rationalism in its modern form post-dates antiquity, philosophers from this time laid down the foundations of rationalism. In particular, the understanding that we may be aware of knowledge available only through the use of rational thought.{{Citation needed|date=April 2018}}

====Pythagoras (570–495 BCE)====
{{Main|Pythagoras}}
Pythagoras was one of the first Western philosophers to stress rationalist insight.<ref name="Epistemological rationalism in modern philosophies">{{Cite web|url=https://www.britannica.com/topic/rationalism|title=rationalism &#124; Definition, Types, History, Examples, & Descartes|website=Encyclopædia Britannica|date=28 May 2023|access-date=14 May 2021|archive-date=18 May 2015|archive-url=https://web.archive.org/web/20150518105808/https://www.britannica.com/EBchecked/topic/492034/rationalism|url-status=live}}</ref> He is often revered as a great [[mathematician]], [[mysticism|mystic]] and [[scientist]], but he is best known for the [[Pythagorean theorem]], which bears his name, and for discovering the mathematical relationship between the length of strings on lute and the pitches of the notes. Pythagoras "believed these harmonies reflected the ultimate nature of reality. He summed up the implied metaphysical rationalism in the words 'All is number'. It is probable that he had caught the rationalist's vision, later seen by [[Galileo Galilei|Galileo]] (1564–1642), of a world governed throughout by mathematically formulable laws".<ref name="Epistemological rationalism in ancient philosophies">{{Cite web|url=https://www.britannica.com/topic/rationalism|title=rationalism &#124; Definition, Types, History, Examples, & Descartes &#124; Britannica|website=www.britannica.com|date=28 May 2023|access-date=14 May 2021|archive-date=18 May 2015|archive-url=https://web.archive.org/web/20150518105808/https://www.britannica.com/EBchecked/topic/492034/rationalism|url-status=live}}</ref> It has been said that he was the first man to call himself a philosopher, or lover of wisdom.<ref>[[Cicero]], ''[[Tusculan Disputations]]'', 5.3.8–9 = [[Heraclides Ponticus]] fr. 88 Wehrli, [[Diogenes Laërtius]] 1.12, 8.8, [[Iamblichus]] ''VP'' 58. Burkert attempted to discredit this ancient tradition, but it has been defended by [[C.J. de Vogel]], ''Pythagoras and Early Pythagoreanism'' (1966), pp. 97–102, and C. Riedweg, ''Pythagoras: His Life, Teaching, And Influence'' (2005), p. 92.</ref>

====Plato (427–347 BCE)====
{{Main|Plato}}
[[File:Plato by Raphael.png|thumb|[[Plato]] in ''[[The School of Athens]]'', by [[Raphael]]]]
Plato held rational insight to a very high standard, as is seen in his works such as [[Meno]] and [[The Republic (Plato)|The Republic]]. He taught on the [[Theory of Forms]] (or the Theory of Ideas)<ref>Modern English textbooks and translations prefer "Theory of Forms" to "Theory of Ideas", but the latter has a long and respected tradition starting with Cicero and continuing in German philosophy until present, and some English philosophers prefer this in English too. See W. D. Ross, Plato's Theory of Ideas (1951) and [http://www.philosophyprofessor.com/philosophies/platos-theory-of-forms.php this]{{webarchive|url=https://web.archive.org/web/20110927061811/http://www.philosophyprofessor.com/philosophies/platos-theory-of-forms.php|date=2011-09-27}} reference site.</ref><ref>The name of this aspect of Plato's thought is not modern and has not been extracted from certain dialogues by modern scholars. The term was used at least as early as [[Diogenes Laërtius]], who called it (Plato's) "Theory of Forms:" {{lang|grc|Πλάτων ἐν τῇ περὶ τῶν ἰδεῶν ὑπολήψει}}...., {{cite encyclopedia |title=Plato |encyclopedia=Lives of Eminent Philosophers |volume=Book III Paragraph 15 |pages=}}</ref><ref>Plato uses many different words for what is traditionally called ''form'' in English translations and ''idea'' in German and Latin translations (Cicero). These include ''idéa'', ''morphē'', ''eîdos'', and ''parádeigma'', but also ''génos'', ''phýsis'', and ''[[Ousia|ousía]]''. He also uses expressions such as ''to x auto'', "the x itself" or ''kath' auto'' "in itself". See Christian Schäfer: ''Idee/Form/Gestalt/Wesen'', in ''Platon-Lexikon'', Darmstadt 2007, p. 157.</ref> which asserts that the highest and most fundamental kind of reality is not the material world of change [[allegory of the cave|known to us through sensation]], but rather the abstract, non-material (but [[Ousia|substantial]]) world of forms (or ideas).<ref>''Forms (usually given a capital F) were properties or essences of things, treated as non-material abstract, but substantial, entities. They were eternal, changeless, supremely real, and independent of ordinary objects that had their being and properties by 'participating' in them.'' [http://www.philosophyprofessor.com/philosophies/platos-theory-of-forms.php Plato's theory of forms (or ideas)] {{webarchive|url=https://web.archive.org/web/20110927061811/http://www.philosophyprofessor.com/philosophies/platos-theory-of-forms.php|date=2011-09-27}}.</ref> For Plato, these forms were accessible only to reason and not to sense.<ref name="Epistemological rationalism in ancient philosophies"/> In fact, it is said that Plato admired reason, especially in [[geometry]], so highly that he had the phrase "Let no one ignorant of geometry enter" inscribed over the door to his academy.<ref>{{cite web|url=http://plato-dialogues.org/faq/faq009.htm|title=Plato FAQ: "Let no one ignorant of geometry enter"|first=Bernard F.|last=Suzanne|website=plato-dialogues.org|access-date=2013-05-22|archive-date=2013-05-19|archive-url=https://web.archive.org/web/20130519153541/http://plato-dialogues.org/faq/faq009.htm|url-status=live}}</ref>

====Aristotle (384–322 BCE)====
{{Main|Aristotle}}
[[Aristotle]]'s main contribution to rationalist thinking was the use of [[Syllogism|syllogistic]] logic and its use in argument. Aristotle defines syllogism as "a discourse in which certain (specific) things having been supposed, something different from the things supposed results of necessity because these things are so."<ref>[[Aristotle]], ''Prior Analytics'', 24b18–20.</ref> Despite this very general definition, Aristotle limits himself to categorical syllogisms which consist of three [[categorical proposition]]s in his work ''[[Prior Analytics]]''.<ref>[http://plato.stanford.edu/entries/logic-ancient/#SynSemSen] {{Webarchive|url=https://web.archive.org/web/20180828102117/https://plato.stanford.edu/entries/logic-ancient/#SynSemSen|date=2018-08-28}} Stanford Encyclopedia of Philosophy: ''Ancient Logic'' Aristotle Non-Modal Syllogistic.</ref> These included categorical [[modal logic|modal]] syllogisms.<ref>[http://plato.stanford.edu/entries/logic-ancient/#ModLog] {{Webarchive|url=https://web.archive.org/web/20180828102117/https://plato.stanford.edu/entries/logic-ancient/#ModLog|date=2018-08-28}} Stanford Encyclopedia of Philosophy: ''Ancient Logic'' Aristotle Modal Logic.</ref>

===Middle Ages===
[[File:Avicenna Portrait on Silver Vase - Museum at BuAli Sina (Avicenna) Mausoleum - Hamadan - Western Iran (7423560860).jpg|thumb|[[Ibn Sina]] Portrait on Silver Vase]]
Although the three great Greek philosophers disagreed with one another on specific points, they all agreed that rational thought could bring to light knowledge that was self-evident{{snd}}information that humans otherwise could not know without the use of reason. After Aristotle's death, Western rationalistic thought was generally characterized by its application to theology, such as in the works of [[Augustine of Hippo|Augustine]], the [[Islamic philosopher]] [[Avicenna|Avicenna (Ibn Sina)]], [[Averroes|Averroes (Ibn Rushd)]], and Jewish philosopher and theologian [[Maimonides]]. The [[Waldensians]] sect also incorporated rationalism into their movement.<ref name="Heckethorn 2011 p. 139">{{cite book | last=Heckethorn | first=C.W. | title=The Secret Societies of All Ages & Countries (Two Volumes in One) | publisher=Cosimo Classics | year=2011 | isbn=978-1-61640-555-7 | url=https://books.google.com/books?id=ta-GttanhRYC&pg=PA139 | access-date=2023-02-11 | page=139 | archive-date=2023-02-11 | archive-url=https://web.archive.org/web/20230211004210/https://books.google.com/books?id=ta-GttanhRYC&pg=PA139 | url-status=live }}</ref> One notable event in the Western timeline was the philosophy of [[Thomas Aquinas]] who attempted to merge Greek rationalism and Christian revelation in the thirteenth-century.<ref name="Epistemological rationalism in ancient philosophies"/><ref name="Gill">{{cite book|last=Gill|first=John|title=Andalucía : a cultural history|year=2009|publisher=[[Oxford University Press]]|location=Oxford|isbn=978-0195376104|pages=108–110}}</ref> Generally, the [[Roman Catholic Church]] viewed Rationalists as a threat, labeling them as those who "while admitting revelation, reject from the word of God whatever, in their private judgment, is inconsistent with human reason."<ref>{{cite book|chapter=[[s:Sermons from the Latins/Sermon 26|Low Sunday: Rationalism]] |title=Sermons from the Latins|year=1902|publisher= Benziger Brothers|first=Robert|last=Bellarmine|author-link=Robert Bellarmine}}</ref>

===Classical rationalism===
====René Descartes (1596–1650)====
{{Descartes}}
{{Main|René Descartes}}
Descartes was the first of the modern rationalists and has been dubbed the 'Father of Modern Philosophy.' Much subsequent [[Western philosophy]] is a response to his writings,<ref>[[Bertrand Russell]] (2004) [https://books.google.com/books?id=Ey94E3sOMA0C&pg=PA516 ''History of western philosophy''] {{Webarchive|url=https://web.archive.org/web/20231018123108/https://books.google.com/books?id=Ey94E3sOMA0C&pg=PA516 |date=2023-10-18 }} pp. 511, 516–517</ref><ref>Heidegger [1938] (2002) p. 76 "Descartes... that which he himself founded... modern (and that means, at the same time, Western) metaphysics".</ref><ref name="Britannica">{{cite encyclopedia |first1=Richard A. |last1=Watson |author-link1=Richard Watson (philosopher) |title=René Descartes |encyclopedia=Encyclopædia Britannica |publisher=Encyclopædia Britannica Online. Encyclopædia Britannica Inc |date=31 March 2012 |url=http://www.britannica.com/EBchecked/topic/158787/Rene-Descartes |access-date=31 March 2012 |archive-date=7 May 2015 |archive-url=https://web.archive.org/web/20150507222658/http://www.britannica.com/EBchecked/topic/158787/Rene-Descartes |url-status=live }}</ref> which are studied closely to this day.

Descartes thought that only knowledge of eternal truths{{snd}}including the truths of mathematics, and the epistemological and metaphysical foundations of the sciences{{spaced ndash}} could be attained by reason alone; other knowledge, the knowledge of physics, required experience of the world, aided by the [[scientific method]]. He also argued that although [[dream]]s appear as real as [[Empirical evidence|sense experience]], these dreams cannot provide persons with knowledge. Also, since conscious sense experience can be the cause of illusions, then sense experience itself can be doubtable. As a result, Descartes deduced that a rational pursuit of truth should doubt every belief about sensory reality. He elaborated these beliefs in such works as ''[[Discourse on the Method]]'', ''[[Meditations on First Philosophy]]'', and ''[[Principles of Philosophy]]''. Descartes developed a method to attain truths according to which nothing that cannot be recognised by the intellect (or [[reason]]) can be classified as knowledge. These truths are gained "without any sensory experience", according to Descartes. Truths that are attained by reason are broken down into elements that intuition can grasp, which, through a purely deductive process, will result in clear truths about reality.

Descartes therefore argued, as a result of his method, that reason alone determined knowledge, and that this could be done independently of the senses. For instance, his famous dictum, ''[[cogito ergo sum]]'' or "I think, therefore I am", is a conclusion reached ''[[A priori and a posteriori|a priori]]'' i.e., prior to any kind of experience on the matter. The simple meaning is that doubting one's existence, in and of itself, proves that an "I" exists to do the thinking. In other words, doubting one's own doubting is absurd.<ref name="Epistemological rationalism in modern philosophies"/> This was, for Descartes, an irrefutable principle upon which to ground all forms of other knowledge. Descartes posited a metaphysical [[Cartesian dualism|dualism]], distinguishing between the substances of the human body ("''res extensa''") and the [[mind]] or soul ("''res cogitans''"). This crucial distinction would be left unresolved and lead to what is known as the [[mind–body problem]], since the two substances in the Cartesian system are independent of each other and irreducible.

====Baruch Spinoza (1632–1677)====
{{Main|Philosophy of Spinoza}}
The philosophy of [[Baruch Spinoza]] is a systematic, logical, rational philosophy developed in seventeenth-century [[Europe]].<ref name=tws9904>{{cite news
| author = Lisa Montanarelli (book reviewer)
| title = Spinoza stymies 'God's attorney'&nbsp;– Stewart argues the secular world was at stake in Leibniz face off
| newspaper = San Francisco Chronicle
| date = January 8, 2006
| url = http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2006/01/08/RVGO9GEOKH1.DTL
| access-date = 2009-09-08
| archive-date = 2009-09-03
| archive-url = https://web.archive.org/web/20090903233734/http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2006/01/08/RVGO9GEOKH1.DTL
| url-status = live
}}</ref><ref name=tws07dec212>{{cite web
|author = Kelley L. Ross
|title = Baruch Spinoza (1632–1677)
|quote = While for Spinoza all is God and all is Nature, the active/passive dualism enables us to restore, if we wish, something more like the traditional terms. Natura Naturans is the most God-like side of God, eternal, unchanging, and invisible, while Natura Naturata is the most Nature-like side of God, transient, changing, and visible.
|publisher = History of Philosophy As I See It
|year = 1999
|url = http://www.friesian.com/spinoza.htm
|access-date = 2009-12-07
|archive-date = 2012-01-04
|archive-url = https://web.archive.org/web/20120104193706/http://friesian.com/spinoza.htm
|url-status = live
}}</ref><ref name=tws07dec211>{{cite news
|author = Anthony Gottlieb
|title = God Exists, Philosophically
|quote = Spinoza, a Dutch Jewish thinker of the 17th century, not only preached a philosophy of tolerance and benevolence but actually succeeded in living it. He was reviled in his own day and long afterward for his supposed atheism, yet even his enemies were forced to admit that he lived a saintly life.
|publisher = The New York Times: Books
|date = July 18, 1999
|url = http://www.times.com/books/99/07/18/reviews/990718.18gottlit.html
|access-date = 2009-12-07
|archive-date = 2023-10-18
|archive-url = https://web.archive.org/web/20231018123108/https://archive.nytimes.com/www.nytimes.com/books/99/07/18/reviews/990718.18gottlit.html
|url-status = live
}}</ref> Spinoza's philosophy is a system of ideas constructed upon basic building blocks with an internal consistency with which he tried to answer life's major questions and in which he proposed that "God exists only philosophically."<ref name=tws07dec211/><ref name=tws908/> He was heavily influenced by Descartes,<ref name=tws07dec114>{{cite news
|author = Michael LeBuffe (book reviewer)
|title = Spinoza's Ethics: An Introduction, by Steven Nadler
|quote = Spinoza's Ethics is a recent addition to Cambridge's Introductions to Key Philosophical Texts, a series developed for the purpose of helping readers with no specific background knowledge to begin the study of important works of Western philosophy...
|publisher = University of Notre Dame
|date = 2006-11-05
|url = http://ndpr.nd.edu/review.cfm?id=8004
|access-date = 2009-12-07
|archive-date = 2011-06-15
|archive-url = https://web.archive.org/web/20110615071049/http://ndpr.nd.edu/review.cfm?id=8004
|url-status = dead
}}</ref> [[Euclid]]<ref name=tws908>{{cite news
| author = Anthony Gottlieb
| title = God Exists, Philosophically (review of "Spinoza: A Life" by Steven Nadler)
| publisher = The New York Times&nbsp;– Books
| date = 2009-09-07
| url = https://www.nytimes.com/books/99/07/18/reviews/990718.18gottlit.html
| access-date = 2009-09-07
| archive-date = 2009-04-17
| archive-url = https://web.archive.org/web/20090417015246/http://www.nytimes.com/books/99/07/18/reviews/990718.18gottlit.html
| url-status = live
}}</ref> and [[Thomas Hobbes]],<ref name=tws07dec114/> as well as theologians in the Jewish philosophical tradition such as [[Maimonides]].<ref name=tws07dec114/> But his work was in many respects a departure from the [[Judeo-Christian-Islamic]] tradition. Many of Spinoza's ideas continue to vex thinkers today and many of his principles, particularly regarding the [[emotions]], have implications for modern approaches to [[psychology]]. To this day, many important thinkers have found Spinoza's "geometrical method"<ref name=tws07dec211/> difficult to comprehend: [[Johann Wolfgang von Goethe|Goethe]] admitted that he found this concept confusing.{{Citation needed|date=June 2015}} His ''[[Masterpiece|magnum opus]]'', ''[[Ethics (Spinoza book)|Ethics]]'', contains unresolved obscurities and has a forbidding mathematical structure modeled on Euclid's geometry.<ref name=tws908/> Spinoza's philosophy attracted believers such as [[Albert Einstein]]<ref name=tws9903>{{cite news
| title = Einstein Believes in 'Spinoza's God'; Scientist Defines His Faith in Reply, to Cablegram From Rabbi Here. Sees a Divine Order But Says Its Ruler Is Not Concerned 'Wit Fates and Actions of Human Beings'.
| newspaper = The New York Times
| date = April 25, 1929
| url = http://select.nytimes.com/gst/abstract.html?res=F10B1EFC3E54167A93C7AB178FD85F4D8285F9
| access-date = 2009-09-08
| archive-date = 2011-05-13
| archive-url = https://web.archive.org/web/20110513034043/http://select.nytimes.com/gst/abstract.html?res=F10B1EFC3E54167A93C7AB178FD85F4D8285F9
| url-status = live
}}</ref> and much intellectual attention.<ref name=tws9902>{{cite news
| title = Spinoza, "God-Intoxicated Man"; Three Books Which Mark the Three Hundredth Anniversary of the Philosopher's Birth 'Blessed Spinoza. A Biography'. By Lewis Browne. 319 pp. New York: Macmillan. 'Spinoza. Liberator of God and Man'. By Benjamin De Casseres, 145 pp. New York: E. Wickham Sweetland. 'Spinoza'. By Frederick Kettner. Introduction by Nicholas Roerich, New Era Library. 255 pp. New York: Roerich Museum Press. 'Spinoza'
| newspaper = The New York Times
| date = November 20, 1932
| url = http://select.nytimes.com/gst/abstract.html?res=F40A14F83A5513738DDDA90A94D9415B828FF1D3
| access-date = 2009-09-08
| first = Percy
| last = Hutchison
| archive-date = 2010-03-26
| archive-url = https://web.archive.org/web/20100326014329/http://select.nytimes.com/gst/abstract.html?res=F40A14F83A5513738DDDA90A94D9415B828FF1D3
| url-status = live
}}</ref><ref name=tws9910>{{cite news
| title = Spinoza's First Biography Is Recovered; The Oldest Biography of Spinoza Edited with Translations, Introduction, Annotations, &c., by A. Wolf. 196 pp. New York: Lincoln Macveagh. The Dial Press.
| newspaper = The New York Times
| date = December 11, 1927
| url = http://select.nytimes.com/gst/abstract.html?res=F60D1EFF395C147A93C3A81789D95F438285F9
| access-date = 2009-09-08
| archive-date = 2010-03-26
| archive-url = https://web.archive.org/web/20100326014335/http://select.nytimes.com/gst/abstract.html?res=F60D1EFF395C147A93C3A81789D95F438285F9
| url-status = live
}}</ref><ref name=tws9901>{{cite news
| author = Irwin Edman
| title = The Unique and Powerful Vision of Baruch Spinoza; Professor Wolfson's Long-Awaited Book Is a Work of Illuminating Scholarship. (Book review) 'The Philosophy of Spinoza. By Henry Austryn Wolfson
| newspaper = The New York Times
| date = July 22, 1934
| url = http://select.nytimes.com/gst/abstract.html?res=FB0610FC395D13728DDDAB0A94DF405B848FF1D3
| access-date = 2009-09-08
| archive-date = 2010-03-26
| archive-url = https://web.archive.org/web/20100326020800/http://select.nytimes.com/gst/abstract.html?res=FB0610FC395D13728DDDAB0A94DF405B848FF1D3
| url-status = live
}}</ref><ref name=tws9908>{{cite news
| title = Roth Evaluates Spinoza
| newspaper = Los Angeles Times
| date = September 8, 1929
| url = https://pqasb.pqarchiver.com/latimes/access/370934682.html?dids=370934682:370934682&FMT=ABS&FMTS=ABS:AI&type=historic&date=Sep+08%2C+1929&author=&pub=Los+Angeles+Times&desc=ROTH+EVALUATES+SPINOZA&pqatl=google
| access-date = 2009-09-08
| first = M E
| last = Cummings
| archive-date = 2010-03-24
| archive-url = https://web.archive.org/web/20100324043102/http://pqasb.pqarchiver.com/latimes/access/370934682.html?dids=370934682:370934682&FMT=ABS&FMTS=ABS:AI&type=historic&date=Sep+08%2C+1929&author=&pub=Los+Angeles+Times&desc=ROTH+EVALUATES+SPINOZA&pqatl=google
| url-status = dead
}}</ref><ref name=tws9906>{{cite news
| author = Social News Books
| title = Tribute to Spinoza Paid by Educators; Dr. Robinson Extols Character of Philosopher, 'True to the Eternal Light Within Him.' Hailed as 'Great Rebel'; De Casseres Stresses Individualism of Man Whose Tercentenary Is Celebrated at Meeting.
| newspaper = The New York Times
| date = November 25, 1932
| url = http://select.nytimes.com/gst/abstract.html?res=F30D13F6355516738DDDAC0A94D9415B828FF1D3
| access-date = 2009-09-08
| archive-date = 2010-03-26
| archive-url = https://web.archive.org/web/20100326020755/http://select.nytimes.com/gst/abstract.html?res=F30D13F6355516738DDDAC0A94D9415B828FF1D3
| url-status = live
}}</ref>

====Gottfried Leibniz (1646–1716)====
{{Main|Gottfried Leibniz}}
Leibniz was the last major figure of seventeenth-century rationalism who contributed heavily to other fields such as [[metaphysics]], [[epistemology]], [[logic]], [[mathematics]], [[physics]], [[jurisprudence]], and the [[philosophy of religion]]; he is also considered to be one of the last "universal geniuses".<ref name="Gottfried Wilhelm Leibniz">Stanford Encyclopedia of Philosophy: [http://plato.stanford.edu/entries/leibniz/ Gottfried Wilhelm Leibniz] {{Webarchive|url=https://web.archive.org/web/20200805133308/http://plato.stanford.edu/entries/leibniz/ |date=2020-08-05 }}.</ref> He did not develop his system, however, independently of these advances. Leibniz rejected Cartesian dualism and denied the existence of a material world. In Leibniz's view there are infinitely many simple substances, which he called "[[Monadology|monads]]" (which he derived directly from [[Proclus]]).

Leibniz developed his theory of monads in response to both Descartes and [[Spinoza]], because the rejection of their visions forced him to arrive at his own solution. Monads are the fundamental unit of reality, according to Leibniz, constituting both inanimate and animate objects. These units of reality represent the universe, though they are not subject to the laws of causality or space (which he called "[[well-founded phenomenon|well-founded phenomena]]"). Leibniz, therefore, introduced his principle of [[pre-established harmony]] to account for apparent causality in the world.

====Immanuel Kant (1724–1804)====
{{Immanuel Kant}}
{{Main|Immanuel Kant}}
Kant is one of the central figures of modern [[philosophy]], and set the terms by which all subsequent thinkers have had to grapple. He argued that human perception structures natural laws, and that reason is the source of morality. His thought continues to hold a major influence in contemporary thought, especially in fields such as metaphysics, epistemology, ethics, political philosophy, and aesthetics.<ref>{{cite web |url=http://plato.stanford.edu/entries/kant/ |title=Immanuel Kant (Stanford Encyclopedia of Philosophy) |publisher=Plato.stanford.edu |date=20 May 2010 |access-date=2011-10-22 |archive-date=2012-01-12 |archive-url=https://web.archive.org/web/20120112123355/http://plato.stanford.edu/entries/kant/ |url-status=live }}</ref>

Kant named his brand of epistemology "[[Transcendental Idealism]]", and he first laid out these views in his famous work ''[[Critique of Pure Reason|The Critique of Pure Reason]]''. In it he argued that there were fundamental problems with both rationalist and empiricist dogma. To the rationalists he argued, broadly, that pure reason is flawed when it goes beyond its limits and claims to know those things that are necessarily beyond the realm of every possible experience: the [[existence of God]], free will, and the immortality of the human soul. Kant referred to these objects as "The Thing in Itself" and goes on to argue that their status as objects beyond all possible experience by definition means we cannot know them. To the empiricist, he argued that while it is correct that experience is fundamentally necessary for human knowledge, reason is necessary for processing that experience into coherent thought. He therefore concludes that both reason and experience are necessary for human knowledge. In the same way, Kant also argued that it was wrong to regard thought as mere analysis. "In Kant's views, [[A priori and a posteriori|a priori]] concepts do exist, but if they are to lead to the amplification of knowledge, they must be brought into relation with empirical data".<ref>{{Cite web|url=http://abyss.uoregon.edu/~js/glossary/rationalism.html|title=Rationalism|website=abyss.uoregon.edu|access-date=2013-05-22|archive-date=2012-12-27|archive-url=https://web.archive.org/web/20121227102857/http://abyss.uoregon.edu/~js/glossary/rationalism.html|url-status=dead}}</ref>

===Contemporary rationalism===
Rationalism has become a rarer label  of philosophers today; rather many different kinds of specialised rationalisms are identified. For example, [[Robert Brandom]] has appropriated the terms "rationalist expressivism" and "rationalist pragmatism" as labels for aspects of his programme in ''Articulating Reasons'', and identified "linguistic rationalism", the claim that the contents of propositions "are essentially what can serve as both premises and conclusions of inferences", as a key thesis of [[Wilfred Sellars]].<ref>''Articulating reasons'', 2000. Harvard University Press.</ref>

Outside of academic philosophy, some participants in the internet communities surrounding [[LessWrong]] and [[Slate Star Codex]] have described themselves as "rationalists" or the "[[rationalist community]]" in reference to [[rationality]], rather than rationalism.<ref>{{Cite web |title=Rationalist Movement – LessWrong |url=https://www.lesswrong.com/tag/rationalist-movement |access-date=2023-06-19 |website=www.lesswrong.com |language=en |archive-date=2023-06-17 |archive-url=https://web.archive.org/web/20230617203001/https://www.lesswrong.com/tag/rationalist-movement |url-status=live }}</ref><ref>{{Cite news |last=Metz |first=Cade |date=2021-02-13 |title=Silicon Valley's Safe Space |language=en-US |work=The New York Times |url=https://www.nytimes.com/2021/02/13/technology/slate-star-codex-rationalists.html |access-date=2023-06-19 |issn=0362-4331 |archive-date=2021-04-20 |archive-url=https://web.archive.org/web/20210420171731/https://www.nytimes.com/2021/02/13/technology/slate-star-codex-rationalists.html |url-status=live }}</ref><ref>{{cite book | url=https://books.google.com/books?id=YDbyDwAAQBAJ | isbn=9781474608800 | title=The Rationalist's Guide to the Galaxy: Superintelligent AI and the Geeks Who Are Trying to Save Humanity's Future | date=13 June 2019 | publisher=Orion | access-date=23 June 2023 | archive-date=18 May 2023 | archive-url=https://web.archive.org/web/20230518113258/https://books.google.com/books?id=YDbyDwAAQBAJ | url-status=live }}</ref> The term has also been used in this way by critics such as [[Timnit Gebru]].<ref>{{cite web | url=https://washingtonspectator.org/understanding-tescreal-silicon-valleys-rightward-turn/ | title=The Wide Angle: Understanding TESCREAL — Silicon Valley's Rightward Turn | date=May 2023 | access-date=2023-06-06 | archive-date=2023-06-06 | archive-url=https://web.archive.org/web/20230606223259/https://washingtonspectator.org/understanding-tescreal-silicon-valleys-rightward-turn/ | url-status=live }}</ref>

==Criticism==
Rationalism was criticized by American psychologist [[William James]] for being out of touch with reality. James also criticized rationalism for representing the universe as a closed system, which contrasts with his view that the universe is an open system.<ref name="pragmatism">{{cite speech|last=James|first=William|date=November 1906|location=Lowell Institute|title=The Present Dilemma in Philosophy}}</ref>

Proponents of [[emotional choice theory]] criticize rationalism by drawing on new findings from emotion research in [[psychology]] and [[neuroscience]]. They point out that the rationalist paradigm is generally based on the assumption that [[decision-making]] is a conscious and reflective process based on thoughts and beliefs. It presumes that people decide on the basis of calculation and deliberation. However, cumulative research in neuroscience suggests that only a small part of the brain's activities operate at the level of conscious reflection. The vast majority of its activities consist of unconscious appraisals and emotions.<ref>See, for example, David D. Franks (2014), "Emotions and Neurosociology", in Jan E. Stets and Jonathan H. Turner, eds., ''Handbook of the Sociology of Emotions'', vol. 2. New York: Springer, p. 267.</ref> The significance of emotions in decision-making has generally been ignored by rationalism, according to these critics. Moreover, emotional choice theorists contend that the rationalist paradigm has difficulty incorporating emotions into its models, because it cannot account for the social nature of emotions. Even though emotions are felt by individuals, psychologists and sociologists have shown that emotions cannot be isolated from the social environment in which they arise. Emotions are inextricably intertwined with people's social norms and identities, which are typically outside the scope of standard rationalist accounts.<ref>See Arlie Russell Hochschild (2012), ''The Managed Heart: Commercialization of Human Feeling'', 3rd ed. Berkeley: University of California Press.</ref> Emotional choice theory seeks to capture not only the social but also the physiological and dynamic character of emotions. It represents a unitary action model to organize, explain, and predict the ways in which emotions shape decision-making.<ref>See [[Robin Markwica]] (2018), ''Emotional Choices: How the Logic of Affect Shapes Coercive Diplomacy''. Oxford: Oxford University Press.</ref>

==See also==
{{columns-list|colwidth=15em|
* [[17th-century philosophy]]
* [[Critical rationalism]]
* [[Emotional choice theory]]
* [[Historical criticism]]
* [[Humanism]]
* [[Idealism]]
* [[Innatism]]
* [[Irrationalism]]
* [[Logical truth]]
* [[Natural philosophy]]
* [[Nominalism]]
* [[Noology]]
* [[Objectivism]]
* [[Objectivity (philosophy)]]
* [[Objectivity (science)]]
* [[Pancritical rationalism]]
* [[Panrationalism]]
* [[Phenomenology (philosophy)]]
* [[Philosophical realism]]
* [[Platonic realism]]
* [[Positivism]]
* [[Psychological nativism]]
* [[Rational choice theory]] 
* [[Rational expectations]]
* [[Rational mysticism]]
* [[Rational realism]]
* [[Rationalist International]]
* ''[[Rationality and Power]]''
* [[Realistic rationalism]]
* [[Pluralistic rationalism]]
* [[Scientific rationalism]]
* [[Theistic rationalism]]
}}

== References ==
{{Reflist}}

==Sources==
===Primary===
* [[René Descartes|Descartes, René]] (1637), ''[[Discourse on the Method]]''.
* [[Baruch Spinoza|Spinoza, Baruch]] (1677), ''[[Ethics (Spinoza)|Ethics]]''.
* [[Gottfried Leibniz|Leibniz, Gottfried]] (1714), ''[[Monadology]]''.
* [[Immanuel Kant|Kant, Immanuel]] (1781/1787), ''[[Critique of Pure Reason]]''.

===Secondary===
* [[Robert Audi|Audi, Robert]] (ed., 1999), ''The Cambridge Dictionary of Philosophy'', [[Cambridge University Press]], Cambridge, 1995. 2nd edition, 1999.
* {{cite book | last = Baird | first = Forrest E. |author2=Walter Kaufmann | title = From Plato to Derrida | publisher = Pearson Prentice Hall | year = 2008 | location = Upper Saddle River, NJ | isbn = 978-0131585911 }}
* [[Simon Blackburn|Blackburn, Simon]] (1996), ''The Oxford Dictionary of Philosophy'', [[Oxford University Press]], Oxford, 1994. Paperback edition with new Chronology, 1996.
* [[Vernon J. Bourke|Bourke, Vernon J.]] (1962), "Rationalism", p.&nbsp;263 in Runes (1962).
* Douglas, Alexander X.: ''Spinoza and Dutch Cartesianism: Philosophy and Theology''. (Oxford: Oxford University Press, 2015)
* {{cite book| last = Fischer| first = Louis| author-link = Louis Fischer| title = The Life of Mahatma Gandhi| publisher = [[HarperCollins]]| year = 1997| pages = 306–307| isbn = 0006388876}}
* Förster, Eckart; Melamed, Yitzhak Y. (eds.): ''Spinoza and [[German Idealism]]''. (Cambridge: Cambridge University Press, 2012)
* Fraenkel, Carlos; Perinetti, Dario; Smith, Justin E. H. (eds.): ''The Rationalists: Between Tradition and Innovation''. (Dordrecht: Springer, 2011)
* Hampshire, Stuart: ''Spinoza and Spinozism''. (Oxford: Clarendon Press; New York: Oxford University Press, 2005)
* Huenemann, Charles; Gennaro, Rocco J. (eds.): ''New Essays on the Rationalists''. (New York: Oxford University Press, 1999)
* Lacey, A.R. (1996), ''A Dictionary of Philosophy'', 1st edition, Routledge and Kegan Paul, 1976. 2nd edition, 1986. 3rd edition, Routledge, London, 1996.
* Loeb, Louis E.: ''From Descartes to Hume: Continental Metaphysics and the Development of Modern Philosophy''. (Ithaca, New York: Cornell University Press, 1981)
* Nyden-Bullock, Tammy: ''Spinoza's Radical Cartesian Mind''. (Continuum, 2007)
* Pereboom, Derk (ed.): ''The Rationalists: Critical Essays on Descartes, Spinoza, and Leibniz''. (Lanham, MD: Rowman & Littlefield, 1999)
* Phemister, Pauline: ''The Rationalists: Descartes, Spinoza and Leibniz''. (Malden, MA: Polity Press, 2006)
* [[Dagobert D. Runes|Runes, Dagobert D.]] (ed., 1962), ''Dictionary of Philosophy'', Littlefield, Adams, and Company, Totowa, NJ.
* Strazzoni, Andrea: ''Dutch Cartesianism and the Birth of Philosophy of Science: A Reappraisal of the Function of Philosophy from Regius to 's Gravesande, 1640–1750''. (Berlin: De Gruyter, 2018)
* Verbeek, Theo: ''Descartes and the Dutch: Early Reactions to Cartesian Philosophy, 1637–1650''. (Carbondale: Southern Illinois University Press, 1992)

==External links==
{{Commonscat}}
{{Wikiquote}}
* {{cite SEP |url-id=rationalism-empiricism |title=Rationalism vs. Empiricism}}
* {{PhilPapers|category|rationalism}}
* {{InPho|taxonomy|2382}}
* {{cite IEP |url-id=cont-rat |title=Continental Rationalism |last=Homan |first=Matthew}}
* {{cite SEP |url-id=continental-rationalism |title=Continental Rationalism |last=Lennon |first=Thomas M.|last2=Dea |first2=Shannon}}
* John F. Hurst (1867), ''[https://www.gutenberg.org/ebooks/19397 History of Rationalism Embracing a Survey of the Present State of Protestant Theology]''

{{Philosophy of science}}
{{Epistemology}}
{{Philosophy topics}}
{{Western culture}}
{{Catholic philosophy footer}}
{{Authority control}}

[[Category:Rationalism| ]]
[[Category:Epistemological theories]]
[[Category:Philosophical schools and traditions]]
[[Category:Reasoning]]