The aim of this article is to investigate the sensualist naturalism in the Logic of the priest and French philosopher Étienne Bonnot de Condillac. This author has been very little studied in our language; being almost non-existent in philosophy journals published in the Hispanic world. This paper is divided into four parts. A first part, where whoever reads us will find the most general naturalism as the humus of the logic written by Mureaux’s priest. In the second part, we will (...) study the reasons for the sensualist qualifier that underlies this original logic and, finally, in the third part, we will show how to articulate the images, genres, classes in the simplified language of a logic that is in accordance with the sensitive organic system of the human being, along with the other important sciences. We will finish this work with our conclusions on how Condillac, moved by his naturalistic and sensualistic background, admonished the essentialist and synthesist logic of his time, rehearsing a renewal through an unusual critical sagacity. (shrink)