This is a reading of Gilles Deleuze’s masterpiece Logic of Sense. It provides a thorough and systematic reading of Deleuze’s book by focusing on the aspects that are neglected in the existing literature. Specifically, the claim that Deleuze’s Logic of Sense provides a convincing answer for the most important question of the history of philosophy regarding the relation between thought and existence as well as the relation between logic and ontology is defended. The answer is that if thought is related to existence, logic is supposed to be, not the logic of essence, but rather the logic of sense. This analysis s pursued respectively through Deleuze’s readings of Frege, the ancient Stoics, Lewis Carroll, Kant, Lautman, Leibniz, and Melanie Klein.