3. Some idea of love as being a person's life may be had from the warmth of the sun in the world. People know that that warmth is, so to speak, the common life of all plant growth of the earth, for whenever it increases, as it does in springtime, plants of every kind rise up from the ground, are adorned with leaves, then flowers, and finally fruits, and so become in a way alive. On the other hand, when the warmth wanes, as it does in autumn and winter, the plants are divested of these signs of life and wither. The same is the case with love in a person, for love and warmth correspond to each other. So it is, too, that love is warm.