Empiricism

===Pragmatism===
In the late 19th and early 20th century, several forms of [[pragmatism|pragmatic philosophy]] arose.  The ideas of pragmatism, in its various forms, developed mainly from discussions between [[Charles Sanders Peirce]] and [[William James]] when both men were at Harvard in the 1870s.  James popularized the term "pragmatism", giving Peirce full credit for its patrimony, but Peirce later demurred from the tangents that the movement was taking, and redubbed what he regarded as the original idea with the name of "pragmaticism".  Along with its ''[[pragmatic theory of truth]]'', this perspective integrates the basic insights of empirical (experience-based) and [[rationalism|rational]] (concept-based) thinking.

[[File:Charles Sanders Peirce theb3558.jpg|thumb|upright|[[Charles Sanders Peirce]]]]
Charles Peirce (1839–1914) was highly influential in laying the groundwork for today's empirical [[scientific method]].<ref>{{Cite book |url=https://plato.stanford.edu/archives/fall2017/entries/peirce/ |title=The Stanford Encyclopedia of Philosophy|last=Burch|first=Robert|date=2017|publisher=Metaphysics Research Lab, Stanford University|editor-last=Zalta|editor-first=Edward N.|edition=Fall 2017}}</ref> Although Peirce severely criticized many elements of Descartes' peculiar brand of rationalism, he did not reject rationalism outright.  Indeed, he concurred with the main ideas of rationalism, most importantly the idea that rational concepts can be meaningful and the idea that rational concepts necessarily go beyond the data given by empirical observation.  In later years he even emphasized the concept-driven side of the then ongoing debate between strict empiricism and strict rationalism, in part to counterbalance the excesses to which some of his cohorts had taken pragmatism under the "data-driven" strict-empiricist view.

Among Peirce's major contributions was to place [[inductive reasoning]] and [[deductive reasoning]] in a complementary rather than competitive mode, the latter of which had been the primary trend among the educated since David Hume wrote a century before.  To this, Peirce added the concept of [[abductive reasoning]].  The combined three forms of reasoning serve as a primary conceptual foundation for the empirically based scientific method today.  Peirce's approach "presupposes that (1) the objects of knowledge are real things, (2) the characters (properties) of real things do not depend on our perceptions of them, and (3) everyone who has sufficient experience of real things will agree on the truth about them.  According to Peirce's doctrine of [[fallibilism]], the conclusions of science are always tentative. The rationality of the scientific method does not depend on the certainty of its conclusions, but on its self-corrective character: by continued application of the method science can detect and correct its own mistakes, and thus eventually lead to the discovery of truth".<ref>Ward, Teddy (n.d.), "Empiricism", [http://personal.ecu.edu/mccartyr/american/leap/empirici.htm Eprint] {{Webarchive|url=https://archive.today/20120714183655/http://personal.ecu.edu/mccartyr/american/leap/empirici.htm |date=2012-07-14 }}.</ref>

[[File:Wm james.jpg|thumb|upright|right|[[William James]]]]
In his Harvard "Lectures on Pragmatism" (1903), Peirce enumerated what he called the "three cotary propositions of pragmatism" ([[Latin|L:]] ''cos, cotis'' whetstone), saying that they "put the edge on the [[pragmatic maxim|maxim of pragmatism]]".  First among these, he listed the peripatetic-thomist observation mentioned above, but he further observed that this link between sensory perception and intellectual conception is a two-way street.  That is, it can be taken to say that whatever we find in the intellect is also incipiently in the senses.  Hence, if theories are theory-laden then so are the senses, and perception itself can be seen as a species of [[abductive reasoning|abductive inference]], its difference being that it is beyond control and hence beyond critique—in a word, incorrigible.  This in no way conflicts with the fallibility and revisability of scientific concepts, since it is only the immediate percept in its unique individuality or "thisness"—what the [[Scholastics]] called its ''[[haecceity]]''—that stands beyond control and correction.  Scientific concepts, on the other hand, are general in nature, and transient sensations do in another sense find correction within them.  This notion of perception as abduction has received periodic revivals in [[artificial intelligence]] and [[cognitive science]] research, most recently for instance with the work of [[Irvin Rock]] on ''[[indirect perception]]''.<ref>Rock, Irvin (1983), The Logic of Perception, MIT Press, Cambridge, Massachusetts.{{page needed|date=December 2013}}</ref><ref>Rock, Irvin, (1997) Indirect Perception, MIT Press, Cambridge, Massachusetts.{{page needed|date=December 2013}}</ref>

Around the beginning of the 20th century, William James (1842–1910) coined the term "[[radical empiricism]]" to describe an offshoot of his form of pragmatism, which he argued could be dealt with separately from his pragmatism—though in fact the two concepts are intertwined in James's published lectures. James maintained that the empirically observed "directly apprehended universe needs ... no extraneous trans-empirical connective support",<ref>James, William (1911), The Meaning of Truth.</ref> by which he meant to rule out the perception that there can be any [[value added]] by seeking [[supernatural]] explanations for [[nature|natural]] [[phenomena]].  James' "radical empiricism" is thus ''not'' radical in the context of the term "empiricism", but is instead fairly consistent with the modern use of the term "[[empirical]]". His method of argument in arriving at this view, however, still readily encounters debate within philosophy even today.

[[John Dewey]] (1859–1952) modified James' pragmatism to form a theory known as [[instrumentalism]].  The role of sense experience in Dewey's theory is crucial, in that he saw experience as unified totality of things through which everything else is interrelated.  Dewey's basic thought, in accordance with empiricism, was that [[reality]] is determined by past experience.  Therefore, humans adapt their past experiences of things to perform experiments upon and test the pragmatic values of such experience.  The value of such experience is measured experientially and scientifically, and the results of such tests generate ideas that serve as instruments for future experimentation,<ref>Dewey, John (1906), Studies in Logical Theory.{{page needed|date=December 2013}}</ref> in physical sciences as in ethics.<ref>{{cite journal |doi=10.1353/jsp.2011.0000 |title=What Experimentalism Means in Ethics |year=2011 |last1=Weber |first1=Eric Thomas |journal=The Journal of Speculative Philosophy |volume=25 |pages=98–115|s2cid=144868257 }}</ref>  Thus, ideas in Dewey's system retain their empiricist flavour in that they are only known ''a posteriori''.