In Différence et répétition, Deleuze's ontology is structured by his theory of dialectical Ideas or problems, which draws features from Plato, Kant, and classical calculus. Deleuze unifies these features through a theory of Ideas/problems developed by the mathematician and philosopher Albert Lautman. Lautman worked to explain the nature of the problems or dialectical Ideas mathematics engages and the solutions or mathematical theories endeavouring to understand them. Lautman drew upon Heidegger to do this. This article clarifies Deleuze's theory of dialectical Ideas/problems (...) by analysing its debts to Lautman and Heidegger and demonstrates a Heideggerian influence on Deleuze via Lautman. (shrink)