When does a thing exist potentially?

What is “actual”?

We must distinguish when a thing exists potentially and when it does not. For it is not at any and every time.

For example, the earth is not potentially a man. The earth cannot turn into a human.

Likewise, not everything can be healed by the medical art or by luck.

• Some bodies can be restore to health. Only these are potentially healthy.

A healer’s thought becomes real if:

• the healer wills it and nothing external hinders it
• the patient does not hinder it

Similarly, a house can be built if the matter allows it.

The same is true of all other things the source of whose becoming is external.

Sometimes, the source of the becoming is in the very thing which comes to be.

The thing can potentially be all those things that it can be if nothing external hinders it.

For example, the seed is not yet potentially a man. It must be deposited in something other than itself and undergo a change.

But when through its own motive principle it has already got such and such attributes, in this state it is already potentially a man.

While in the former state it needs another motive principle, just as earth is not yet potentially a statue (for it must first change in order to become brass.)

When we call a thing not something else but ’thaten’-e.g. a casket is not ‘wood’ but ‘wooden’, and wood is not ’earth’ but ’earthen’, and again earth will illustrate our point if it is similarly not something else but ’thaten’-that other thing is always potentially (in the full sense of that word) the thing which comes after it in this series.

E.g. a casket is not ’earthen’ nor ’earth’, but ‘wooden’.

This is potentially a casket and this is the matter of a casket, wood in general of a casket in general, and this particular wood of this particular casket.

If there is a first thing, which is no longer, in reference to something else, called ’thaten’, this is prime matter; e.g. if earth is ‘airy’ and air is not ‘fire’ but ‘fiery’, fire is prime matter, which is not a ’this’.

For the subject or substratum is differentiated by being a ’this’ or not being one; i.e. the substratum of modifications is, e.g. a man, i.e. a body and a soul, while the modification is ‘musical’ or ‘pale’.

(The subject is called, when music comes to be present in it, not ‘music’ but ‘musical’, and the man is not ‘paleness’ but ‘pale’, and not ‘ambulation’ or ‘movement’ but ‘walking’ or ‘moving’,-which is akin to the ’thaten’.)

Wherever this is so, then, the ultimate subject is a substance; but when this is not so but the predicate is a form and a ’this’, the ultimate subject is matter and material substance. And it is only right that ’thaten’ should be used with reference both to the matter and to the accidents; for both are indeterminates.

Thus we now know when a thing exists potentially and when it is not.