 In More’s mature philosophy, then, there was a strict dichotomy between matter and spirit but that dichotomy was not defined, as it was in Cartesianism, in terms of extension and non-extension. Because More was committed to the idea that all real entities must exist in space, spirit, no less than body, was extended. Accordingly, body was defined as “A Substance impenetrable and discerpible”, and spirit as “A Substance penetrable and indiscerpible”. Discerpible and indiscerpible, neologisms of More’s, mean capable of being physically separated into parts, and incapable of being separated into parts, respectively. Presumably More preferred his new terms because, for those readers who knew Latin, it conveyed a notion of tearing a piece off. More perhaps wanted to avoid objections to the indivisibility of extended spirits of the kind levelled against the concept of atoms: if an atom has dimensions, however small, it is conceptually divisible, even if atomists wish to claim it is physically indivisible. More conceded that an extended spirit could be conceptually divided, but his point was that it is impossible (even in thought) to grab hold of a spirit and tear a piece off it. If you are thinking in those terms, you are not thinking properly about the nature of spirit. The other major distinguishing feature of body and spirit, of course, as we have seen, was that bodies were inert and passive, and immaterial spirits were naturally active, and indeed increasingly responsible, throughout More’s career, for any activity in the world (Henry 1986; Reid 2003, 2012; Leech 2013). 