  These difficulties in accounting for substance on Malebranche’s part seem to derive from his Platonism. As a Platonist, he was interested less in substance as the hypokeimenon, which accounts for difference, than in its other sense of ousia, which accounts for sameness. Thus, Malebranche’s skid to Spinozism is greased even when he talks about mind, the essence of which is thought—not this or that thought, “but substantial thought, thought capable of all sorts of modifications or thoughts”. Since the same substantial thought is had by all possessed of a mind, Malebranche’s view smacks even of the single intellectual soul for all human beings of the Latin Averroists. In this sense too, then, his heterodoxy as a Cartesian is part and parcel with his deep commitment to rationalism, and in particular with his rationalistic reduction of phenomenal difference to real sameness.