 A serious objection to position (4) is that it apparently leads to a vicious infinite regress: if a compound’s essence or form is itself a compound of matter and form, and this second form has an essence or form which is also a hylomorphic compound, etc., every compound will have an infinite series of essences or forms associated with it. Socrates is (essentially) a compound of matter and form, so is his form, so is its form, etc. Note that this regress only applies if all forms are held to be matter-involving. It does not afflict the more moderate matter-involving position, (2), since it holds that the form of the compound is matter-involving, and hence has both material and formal parts, but that this second form, the form of the form, is pure, and has itself as a form, e.g., the form of a computer may be computing functions in certain suitable matter, but the formal part of that form (computing functions) would be pure. The regress is not merely unattractively bloated and otiose. If a full explanation of what something is requires one to list an infinite series of forms, such explanations will not be viable for finite beings like us.