Well, we have seen that certain entities, which are objects of sense or of thought, or of both, can disappear from the individual without the residue thereby perishing or ceasing to exist actually as an individual: the human soul survives, as an actual individual reality, after its separation from the material principle with which it formed the individual man; the individual man persists while the accidental modes that affect him disappear. In such cases as these, intellect, interpreting sense experience and reasoning from it, places a real distinction, in the composite individual, between the factors that can continue to exist without others, and these latter. In doing so it is apparently applying the analogy of the typical real distinction—that between one individual and another. The factor, or group of factors, which can continue to exist actually after the separation of the others, is an individual: and what were separated from it were apparently real entities, though they may have perished by the actual separation. But on what ground is the distinction between the material principle and the vital principle of a plant or an animal, for example, regarded as real? Again on the ground furnished by the analogy of the distinction between individuals of sense experience. Note that it is not between the material and the vital principles _as objects of abstract thought_, _i.e._ between the _materiality_ and the _vitality_ of the plant or the animal, that a real distinction is claimed: these are regarded only as conceptually distinct aspects of the plant or the animal; nor is it admitted that because one of these thought-objects is found embodied elsewhere in nature without the other—materiality without vitality in the inorganic universe—we can therefore conclude that they are really distinct in the plant or the animal. No; it is between the two principles conceived as coexisting and united in the concrete individual that the real distinction is claimed. And it is held to be a real distinction because substantial change in corporeal things, _i.e._ corruption and generation of individual corporeal substances, is held to be real. If it is real there is a real separation of essential factors when the individual perishes. And the factors continue to be real, as _potential_ principles of other individuals, when any individual corporeal substance perishes. Each principle may not continue to exist actually as such in isolation from the other—though some scholastics hold that, absolutely speaking, they could be conserved apart, as actual entities, by the Author of Nature. But they _can_ actually exist _as essential principles of other actual individuals_: they are real _potentialities_, which _become actual_ in other individuals. Thus we see that they are conceived throughout _after