Abstract
The Logic or the Art of Thinking, also called Port-Royal Logic, is an exemplar of modern reformers in logic and epistemology. Its reformism has a marked influence of Descartes, who introduces the epistemic and logical subject into the ground of justification of knowledge and judgment. A look at the method’s commitments in this text may shed light on the dynamics of the interweaving between epistemology and logic. It is in this perspective that an analysis of the use of the Aristotelian notion of “techné”, as an “art of doing anything well” seems to require attention, since it happens in a logical domain, as the authors make it. In this paper I want to make clear that the mental actions are crucial to a logic as reflexive practice. And, because of that, the very expression of “art of thinking” shows itself as non-trivial, that is, as a requirement of method.