Abstract
In this article, I consider the significance of the discovery of spermatozoa for Leibniz's deeply held beliefs that (i) no true substance can ever be generated or destroyed, except miraculously; and (ii) that every substance must be perpetually organically embodied. I further consider the way these beliefs are transformed as Leibniz's basic middle-period commitment to corporeal substance gives way (though not entirely) to a metaphysics of monadological immaterialsm. What endures throughout, I show, is the conviction that whatever is real must be indestructible, whether this is conceived as a form-matter compound in which the two components can never be entirely sundered from one another, or as a node of perception “absolutely destitute of parts”. Whatever the deepest metaphysical account of corporeality, Leibniz never abandons his interest in spermatozoa as the corporeal hosts of preexisting animals.