3.13.1
Solitude is a certain condition of a helpless man. For because a man is alone, he is not for that reason also solitary; just as though a man is among numbers, he is not therefore not solitary. When then we have lost either a brother, or a son or a friend on whom we were accustomed to repose, we say that we are left solitary, though we are often in Rome, though such a crowd meet us, though so many live in the same place, and sometimes we have a great number of slaves. For the man who is solitary, as it is conceived, is considered to be a helpless person and exposed to those who wish to harm him. For this reason when we travel, then especially do we say that we are lonely when we fall among robbers, for it is not the sight of a human creature which removes us from solitude, but the sight of one who is faithful and modest and helpful For if being alone is enough to make solitude, you may say that even Zeus is solitary in the conflagration and bewails himself saying, Unhappy that I am who have neither Hera, nor Athena, nor Apollo, nor brother, nor son, nor descendant nor kinsman. This is what some say that he does when he is alone at the conflagration. For they do not understand how a man passes his life when he is alone, because they set out from a certain natural principle, from the natural desire of community and mutual love and from the pleasure of conversation among men. But none the less a man ought to be prepared in a manner for this also (being alone), to be able to be sufficient for himself and to be his own companion. For as Zeus dwells with himself, and is tranquil by himself, and thinks of his own administration and of its nature, and is employed in thoughts suitable to himself; so ought we also to be able to talk with ourselves, not to feel the want of others also, not to be unprovided with the means of passing our time; to observe the divine administration, and the relation of ourselves to every thing else; to consider how we formerly were affected towards things that happen and how at present; what are still the things which give us pain; how these also can be cured and how removed; if any things require improvement, to improve them according to reason.