Let there be two possible things, A and B, one of which is such that it is necessary that it exists, and let us assume that there is more perfection in A than in B. Then, at least, we can explain why A should exist rather than B and can foresee which of them will exist; indeed, this can be demonstrated, that is, rendered certain from the nature of the thing.
Gottfried Leibniz[Alternate translation:] The Divine Spirit found a sublime outlet in that wonder of analysis, that portent of the ideal world, that amphibian between being and not-being, which we call the imaginary root of negative unity.
Gottfried LeibnizThe words 'Here you can find perfect peace' can be written only over the gates of a cemetery.
Gottfried LeibnizAnd there must be simple substances, because there are compounds; for the compound is nothing but a collection or aggregatum of simples.
Gottfried LeibnizImaginary numbers are a fine and wonderful refuge of the divine spirit almost an amphibian between being and non-being.
Gottfried LeibnizFor, above all, I hold a notion of possibility and necessity according to which there are some things that are possible, but yet not necessary, and which do not really exist. From this it follows that a reason that always forces a free mind to choose one thing over another (whether that reason derives from the perfection of a thing, as it does in God, or from our imperfection) does not eliminate our freedom.
Gottfried Leibniz