  Many scholastics came to understand combination as the coming together of the least parts of the combining substances to form least parts of the compound. These least parts were referred to as natural minima. Substances cannot be divided indefinitely, it was claimed, because division will eventually result in natural minima which are either indivisible or are such that, if divided, no longer constitute a portion of the divided substance. But the theory of natural minima was developed to a stage where it involved more than that. The minima were presumed to exist as parts of a substance quite independent of any process of division. What is more, chemical combination was understood as coming about via the combination of minima of the combining substances forming minima of the compound. Talk of chemical combination taking place ‘per minima’ became common.