Lucretius speaks of it more as a natural philosopher: Virgil follows in the steps of Lucretius; _amor omnibus idem_.
It is the stuff of nature broidered by nature. Do you want an idea of love? look at the sparrows in your garden; look at your pigeons; look at the bull which is brought to the heifer; look at this proud horse which two of your grooms lead to the quiet mare awaiting him; she draws aside her tail to welcome him; see how her eyes sparkle; hark to the neighing; watch the prancing, the curvetting, the ears pricked, the mouth opening with little convulsions, the swelling nostrils, the flaring breath, the manes rising and floating, the impetuous movement with which he hurls himself on the object which nature has destined for him; but be not jealous of him, and think of the advantages of the human species; in love they compensate for all those that nature has given to the animals--strength, beauty, nimbleness, speed.
There are animals, even, who have no enjoyment in possession. Scale fish are deprived of this delight: the female throws millions of eggs on the mud; the male coming across them passes over them, and fertilizes them with his seed, without troubling about the female to whom they belong.
Most animals that pair, taste pleasure only by a single sense, and as soon as the appetite is satisfied, everything is extinguished. No animal, apart from you, knows what kissing is; the whole of your body is sensitive; your lips especially enjoy a voluptuousness that nothing can tire; and this pleasure belongs to no species but yours: you can give yourself up to love at any time, and the animals have but a fixed time. If you reflect on these superiorities, you will say with the Count of Rochester--"In a country of atheists love would cause the Deity to be worshipped."
As men have received the gift of perfecting all that nature accords them, they have perfected love. Cleanliness, the care of oneself, by rendering the skin more delicate, increase the pleasure of contact; and attention to one's health renders the organs of voluptuousness more sensitive. All the other sentiments that enter into that of love, just like metals which amalgamate with gold: friendship, regard, come to help; the faculties of mind and body are still further chains.