Change does not necessarily assure progress, but progress implacably requires change.
Imperfection is in some sort essential to all that we know of life. It is the sign of life in a mortal body, that is to say, of a state of progress and change. Nothing that lives is, or can be rigidly perfect; part of it is decaying, part nascent.
What we call progress is the exchange of one nuisance for another nuisance.