2. We note concerning our bodily nature three things, for the sake of which our particular parts were formed. Life is the cause of some, good life of others, others again are adapted with a view to the succession of descendants. All things in us which are of such a kind that without them it is not possible that human life should exist, we consider as being in three parts; in the brain, the heart, and the liver. Again, all that are a sort of additional blessings, nature’s liberality, whereby she bestows on man the gift of living well, are the organs of sense; for such things do not constitute our life, since even where some of them are wanting man is often none the less in a condition of life; but without these forms of activity it is impossible to enjoy participation in the pleasures of life. The third aim regards the future, and the succession of life. There are also certain other organs besides these, which help, in common with all the others, to subserve the continuance of life, importing by their own means the proper supplies, as the stomach and the lungs, the latter fanning by respiration the fire at the heart, the former introducing the nourishment for the internal organs.