Changes

Descartes concluded that if his goal was to attain certain knowledge about the world, Descartes concluded that the then presently accepted method must be rejected and that a new one would be required to satisfy his aims. Method held a central place in his epistemology; in fact, one of Descartes’ criticisms of Galileo was that he failed to produce a fully developed method to justify his discoveries.[[CiteRef::Ariew (1986)]] To that end he embraced his skeptical doubts and devised a method based on '''methodological skepticism'''; a method whereby he rejects all knowledge that he cannot be certain of, accepts only those propositions which he can accept as certain, and proceed deductively from those axioms according to reason. By this method Descartes hoped to produce a kind of systematized knowledge that, he believed, could be universally acceptable. In his 'Meditations on First Philosophy', [[CiteRef::Descartes (2004)]] Descartes identified the sole indubitable proposition upon which he would build the entire rest of his philosophical system as his famous '''‘Cogito, Ergo Sum’''' (also styled ‘Dubito, Ergo Cogito, Ergo Sum’ or simply as ‘the Cogito’); “I think, therefore I am.” From this foundation Descartes deduced his being a created thing, his requiring a creator, that creator being God, the nature of God, and the reliability of his God-given senses and reason, all of which would form formed the broader foundation of his systematized scientific worldview.[[CiteRef::Newman (2014)]]

Although Descartes maintained some methodological aspects of the Scholastic-Aristotelian mosaic – namely the axiomatic-deductive, epistemic-foundationalist structure of investigation – one critical difference in Descartes’ methodology was the shift in the method of theory choice. According to Barseghyan, the accepted method of the Scholastic-Aristotelian method was that a theory is acceptable “if it grasps the nature of a thing through intuition schooled by experience, or if it is deduced from general intuitive principles”.[[CiteRef::Barseghyan (2015)|p. 144]] The keywords in this formulation of Descartes’ methodology jettisons the Scholastic-Aristotelian method are intuition and experience, both of which are necessary conditions for one to be justified in accepting a proposition. Descartes’ methodology is notable in expectation that it jettisons both of those conditions; a proposition need theory must be neither experientially based nor intuited and intuitively obvious for it to be acceptable, and although his system as it ended up allowed for knowledge that was both experiential and intuited,[[CiteRef::Newman (2014)]] the ultimate justification for knowledge claims was human reason. In this way Descartes is both a '''rationalist''' and an a priorist, in that his epistemology and metaphysics allows for the existence of synthetic a priori propositions.