 Matter for Diderot is self-organizing and endowed with vital properties. This implies that his brand of materialism is not synonymous with  physicalism  (admittedly, not a term or notion of the period). There were of course materialists such as  Hobbes  who can also be described as physicalists, but Diderot was quite explicitly a determinist, as we will discuss below (in  section 2.4).  This leads to two rather original consequences, which we examine in the following sections: Diderot’s metaphysics of vital matter is not strictly experimentally based, it is also speculative; and his is a specifically embodied materialism.