17. What then is love? Will it not be an image? Will it not be a word? Will it not be begotten? For why does the mind beget its knowledge when it knows itself, and not beget its love when it loves itself? For if it is the cause of its own knowing, for the reason that it is knowable, it is also the cause of its own love because it is lovable. It is hard, then, to say why it does not beget both. For there is a further question also respecting the supreme Trinity itself, the omnipotent God the Creator, after whose image man is made, which troubles men, whom the truth of God invites to the faith by human speech; viz. why the Holy Spirit is not also to be either believed or understood to be begotten by God the Father, so that He also may be called a Son. And this question we are endeavoring in some way to investigate in the human mind, in order that from a lower image, in which our own nature itself as it were answers, upon being questioned, in a way more familiar to ourselves, we may be able to direct a more practised mental vision from the enlightened creature to the unchangeable light; assuming, however, that the truth itself has persuaded us, that as no Christian doubts the Word of God to be the Son, so that the Holy Spirit is love. Let us return, then, to a more careful questioning and consideration upon this subject of that image which is the creature, that is, of the rational mind; wherein the knowledge of some things coming into existence in time, but which did not exist before, and the love of some things which were not loved before, opens to us more clearly what to say: because to speech also itself, which must be disposed in time, that thing is easier of explanation which is comprehended in the order of time.