  As for individual substances, Malebranche clearly thought that every material thing and every mind is a substance in the sense of a hypokeimenon. But when pressed late in his life to show how this status for them comported with the rest of his system, how they could be anything but modes of a single substance, in short how he avoided the drift into Spinozistic monism, he was in fact hard pressed.  In the Search After Truth, Malebranche clearly committed himself to the view that everything is either a substance or a mode. In addition, he accepted Descartes’s criterion for a substance that it be conceivable apart from everything else. However, he maintained that any given portion of extension is conceivable apart from the rest of extension and is thus a substance. (Descartes did not think this, otherwise void space would be possible for him.) Since extension is conceptually divisible to infinity, Malebranche is committed to an infinite number of extended substances. Apart from the whole of extension, moreover, every substance contains an infinite number of substances, of (each of) which it is a mode. It is also a part of an infinite number of substances, which are modes of it. The explanatory value of the concept of substance would seem to have been lost with such results as these. Malebranche’s view seems to be a degenerate version of Descartes’s texts to the effect, surprising but coherent, that there is but one material substance, res extensa, whose modes are particular material things. Here the effect is to reverse the Aristotelian logic of substance. To say of \(x\), a particular thing, that it is extended \(E\), is to say not that a substance \(x\) has a property \(E\), but that \(x\) is a mode of res extensa.