Rationalism

Eyes wearing inverted lenses Philosophy of science

Foundations

Empiricism Rationalism Naturalism Materialism

Method

Scientific method Critical thinking A priori and a posteriori Evidence Falsifiability Reproducibility

Conclusions

Theory Law Science v - t - e

Not to be confused with Rationality, which simply refers to the process of being reasonable.

Rationalism is a philosophy in which a high regard is given to reason (specifically logic).

From the strict philosophical standpoint, rationalism is the view that all or most truth is deductive and a priori, deriving logically from a set of axioms gained by intuition or inherent knowledge (and not from studying the world around us empirically). The terms continental rationalism and Cartesian rationalism are sometimes used in reference to the Early Modern school of thought.

The term is more commonly used to refer to a synthesis of continental rationalism with its former rival philosophy, empiricism. This looser rationalism holds that empirical observation is more useful than intuition for gaining one's starting axioms, but one can use deductive reasoning from these axioms just as well. The best embodiment of this way of gaining knowledge is the scientific method; hence, rationalists tend to give high regard to science, designating it as the primary or sole proper source of truth.

RationalWiki is devoted to this sort of rational analysis of empirical evidence to form conclusions; most RationalWiki editors are very skeptical of other ways of knowing.

Definitions

General use

See the main article on this topic: Rationality

The idea of being "rational" is distinct and broader than the philosophy of rationalism. To be "rational" is synonymous with a "sane" or "functional" way of thinking. If one is "rational," then in common parlance this means that one can think clearly and is capable of intelligently assessing new ideas when presented.

The opposite term, "irrational," is used to signify someone who cannot or will not think clearly. If a thought or action is “irrational,” it signifies something that is not just incorrect, but perverse, insane, or beneath consideration.

Historical rationalism

Ideas resembling rationalism were first formulated in classical times. Many of Plato's Socratic dialogues would use a conversational process to work out logical inconsistencies in ideas that were held by contemporaries to be "common sense," such as the definition of "the good." At the time, virtually everyone — even the great philosophers — believed that various things were known by people inherently. Aside from a few schools of thought which suggested that nothing could ever be known as true (pyrrhonism), few thought to discard a priori beliefs and start from scratch with only that which was known from experience.

The 16^th century philosopher Descartes, however, attempted to create a whole philosophy through pure reason in his Discourse on Method and its succeeding works: he began with methodological doubt to ascertain the only thing about which it seemed he could be certain — that there was an "I" that was thinking. His process ushered in a new era in rationalism, concurrent with the greater Enlightenment. At that time the philosophy began to resemble modern empiricism more than its own ancient ancestor, especially during the era of Romanticism when Enlightenment ideas were challenged and sensory perception was given more of a hearing.

Loose use in the time since has led to the fuzzy state of the term today, particularly when combined with the similar but much broader notion of being rational.

Rationalism in psychology

Rationalism in psychology is identified with the philosophical tradition of the same name and refers to the school of thought that sees certain elements of cognition as innate. For this reason, it is sometimes used synonymously with the terms "innatism" or "nativism" though the synonymy is not particularly deep as "innatism" or "nativism" sees them as innate in the thicker sense of that one at least can be born with them preset exactly in a certain, perhaps permanent, way (whether this ever actually happens is beside the point) and Rationalism sees them as innate in the thinner sense that one is simply born with them waiting to be set more exactly as one is psychologically prepares to understand what they are about and perhaps never completely fixable once set for the first time. During the 20th century, Noam Chomsky became associated with rationalism due to his positing the concept of an innate "language acquisition device."

Rationalism in economics

Rationalism, or "economic rationalism," is also a term of art in economics. It is generally used today in Australia to refer to the local brand of neoliberal economic and political policy, though it was also used by scholars such as Max Weber in reference to the Protestant work ethic.

Other contemporary uses

Rationalism is also used as a self-descriptor by followers of Eliezer Yudkowsky, and the community that has grown up around him (in particular the website LessWrong). Scott Alexander argues that, in this context, it refers less to a particular set of beliefs (an ideology), but more to the social community those beliefs support, a "tribe".

Means-ends rationalism

Another straightforward conception of rationality is that an individual acts rationally if they act in the way that, on reflection, they believe best suits achievement of their aims. This conception, naturally, gives rise to the common conception when “on reflection” it is believed that the aim of truth can best be achieved through factual analysis and the scientific method.

This approach, however, is problematic, as it denies the existence of any sort of objective logic independent of human perception. Many, on reflection, believe that astrology, Scientology, homeopathy and other ridiculous nonsense best suits achievement of their aims. If these people are to be held to be irrational, a new criterion must be put in the place of “on reflection”. Usually the criterion is modified such that the rational person must “reasonably believe” they have a methodology to achieve their aims, leaving question of what it means to “reasonably believe” that a methodology will achieve certain aims.

Sanity and proper function

Alvin Plantinga's concept of rationalism neatly distinguishes reason from "raving madness" by conceiving of reason as "not raving mad". Of course, Plantinga has to give us a good idea of what is not "raving mad", which he does with his concept of "proper function". Just as a clock, functioning properly, is a reliable indicator of the time, human senses, functioning properly, are reliable indicators of the world. Acting in accordance with the proper function of our faculties is rational.

The problem of what constitutes function, and proper function at that, is more than a question of what our faculties do (a fast clock tells the incorrect time, but this is not its function). Both function and proper function have an element of what things should be doing. As should is a difficult concept to introduce in a mechanistic description of how things happen to be, Plantinga sources the "should", the "purpose" of our faculties in a concept of God.

Critical rationalism

Critical rationalism (©Karl Popper) differentiates from the above conceptions of rationality by rejecting any positive content in reason. “Reason”, critical rationalism holds, does not provide 'reasons': it does not give positive recommendations about what beliefs should be held. Reason operates negatively, restricting the beliefs that can be held. It does this through criticism, subjecting pre-adopted beliefs to tests in an effort to refute them.

Empiricism versus Rationalism

The dispute between rationalism and empiricism concerns the extent to which we are dependent upon sense experience in our effort to gain knowledge. Rationalists claim that there are significant ways in which our concepts and knowledge are gained independently of sense experience. Empiricists claim that sense experience is the ultimate source of all our concepts and knowledge.

Rationalists generally develop their view in two ways. First, they argue that there are cases where the content of our concepts or knowledge outstrips the information that sense experience can provide. Second, they construct accounts of how reason in some form or other provides that additional information about the world. Empiricists present complementary lines of thought. First, they develop accounts of how experience provides the information that rationalists cite, insofar as we have it in the first place. (Empiricists will at times opt for skepticism as an alternative to rationalism: if experience cannot provide the concepts or knowledge the rationalists cite, then we don't have them.) Second, empiricists attack the rationalists' accounts of how reason is a source of concepts or knowledge.

See also

• Rationality
• Rationalization