Love is a person's life. People know that love exists, but they do not know what love is. They know from common speech that it exists. For instance, people say that he loves me, that a king loves his subjects and the subjects love their king, that a husband loves his wife, and a mother her children, and vice versa; also that this or that person loves his country, his fellow citizens, his neighbor. So, too, in regard to matters apart from person, as when it is said that someone loves this or that thing. But even though love is so frequently mentioned, still scarcely anyone knows what love is. Whenever someone reflects on it, he cannot then form for himself any mental idea of it. Therefore he says either that it is not anything, or that it is merely some stimulus flowing in through his vision, hearing, touch, and social interaction, which thus affects him. He is totally unaware that love is his very life, not only the general life in his whole body and the general life in all his thoughts, but also the life in every single particle of them. This the wise person may perceive from considering the following proposition: If you take away any impulse having to do with love, can you form any thought? Or can you perform any action? Is it not the case that as the affection belonging to love cools, in the same measure thought, speech and action cool? And the warmer the affection grows, the warmer they grow? Still, the wise person perceives this not from any concept that love is a person's life, but from his empirical observation that it is so.