Descartes sometimes writes that the mind is in the body as whole in the whole and whole in the parts. In this sense, he claimed, the mind is extended but in a sense different from body. Henry More labeled this view “holenmerism.” The view had been around since at least Plotinus, and it was used in two contexts that both address the presence of spiritual substances in the physical world. First it was used to describe the way spiritual substances, angels, human souls, and especially God act on bodies. God can act anywhere in the physical world, but his doing so, the argument goes, requires his presence where he acts. God cannot, however, be present in the physical world in the way in which a body is present, that is whole in the whole and part in the part, with parts being distributed, because God has no parts. So the only way God could be present in a multiplicity of physical locations is by being present in his entirety in every one of them (Suárez, Disputationes metaphysicae XXX. VII, Grant 1981).

The second use of holenmerism concerns the presence of the human soul in its body where the issue is not interaction, and this use can be found in Augustine and Plotinus, and in Aristotelian Scholasticism. The human soul is a spiritual substance and does not have parts that can be spread out through the body. Within Scholasticism, the human soul was also a substantial form, but its status as a spiritual substance made it a special one. Thus, Suárez claims that in a plant its soul is present whole in the whole, part in the part. This explains why we can cut off a branch and use it to start a new plant. A part of the soul remains in the branch, and thus it continues to live. But this is not the case for a human being. The case of higher animals was considered to be difficult (Des Chene 2000, ch. 9).