One of the causes of the rebirth that the philosophy of being of Thomas Aquinas has been experiencing since the middle of the last century is, without a doubt, the impact of the studies carried out on this subject by the French medievalist, Étienne Gilson. Spurred on by the onto-theological critique of M. Heidegger, Gilson and other Thomists, made common cause to clarify the scope of the Heideggerian invective, which judged that Aquinas’s metaphysics of being would also have fallen into (...) an essentialism or reification of being. The proposal of these authors focused on highlighting the original notion of being (actus essendi) in front of interpreters (some from the Thomist school itself) who would have obscured its meaning, fundamentally its supreme current value. In the opinion of Gilson, Fabro and others, the main cause of this blurring would be the identification of being and existence. My objective in this article is to critically analyze some positions of contemporary Thomism and justify the impossibility of identifying what Thomas Aquinas calls esse by existence. (shrink)