In general, an imperfection of x cannot be obtained in the absence of a perfection of x. This is most easily seen with noise. There can be no defect of signal if there is no signal in the first place. Likewise you can’t disorder what is not ordered. Nor can you sin if there is no righteousness, or kill what is not alive.
Partiality is another sort of imperfection: you can’t be a part of a whole that is not there to begin with. So likewise, participating a form is impossible if there is no such form.
Then there is incompleteness. What cannot be completed cannot be incomplete, strictly speaking. We can’t count to infinity; if we count to 100, then, we have completed, not part of the count to infinity, but only the count to 100. Likewise, partial knowledge is not knowledge at all in the absence of omniscience.
Our lives are pervasively imperfect. They point always toward perfection. They indicate it; and they aim at it. If there were no such perfection in the first place, there could be no imperfection in our experience, nor therefore any nisus to correct it. If there were no perfection, it could not be a problem for us that we feel we have not achieved it, and we would not feel its lack as painful. Yet we do.
Imperfection presupposes perfection. The latter is therefore prior to the former, and is its forecondition.