3. Some idea of love, as being the life of man, may be had from the sun's heat in the world. This heat is well known to be the common life, as it were, of all the vegetations of the earth. For by virtue of heat, coming forth in springtime, plants of every kind rise from the ground, deck themselves with leaves, then with blossoms, and finally with fruits, and thus, in a sense, live. But when, in the time of autumn and winter, heat withdraws, the plants are stripped of these signs of their life, and they wither. So it is with love in man; for heat and love mutually correspond. Therefore love also is warm.