6.  Whether the universe is [a concourse of] atoms, or nature [is a system], let this first be established, that I am a part of the whole which is governed by nature; next, I am in a manner intimately related to the parts which are of the same kind with myself.  For remembering this, inasmuch as I am a part, I shall be discontented with none of the things which are assigned to me out of the whole; for nothing is injurious to the part if it is for the advantage of the whole.  For the whole contains nothing which is not for its advantage; and all natures indeed have this common principle, but the nature of the universe has this principle besides, that it cannot be compelled even by any external cause to generate anything harmful to itself.  By remembering, then, that I am a part of such a whole, I shall be content with everything that happens.  And inasmuch as I am in a manner intimately related to the parts which are of the same kind with myself, I shall do nothing unsocial, but I shall rather direct myself to the things which are of the same kind with myself, and I shall turn all my efforts to the common interest, and divert them from the contrary.  Now, if these things are done so, life must flow on happily, just as thou mayst observe that the life of a citizen is happy, who continues a course of action which is advantageous to his fellow-citizens, and is content with whatever the state may assign to him.

7.  The parts of the whole, everything, I mean, which is naturally comprehended in the universe, must of necessity perish; but let this be understood in this sense, that they must undergo change.  But if this is naturally both an evil and a necessity for the parts, the whole would not continue to exist in a good condition, the parts being subject to change and constituted so as to perish in various ways.  For whether did Nature herself design to do evil to the things which are parts of herself, and to make them subject to evil and of necessity fall into evil, or have such results happened without her knowing it?  Both these suppositions, indeed, are incredible.  But if a man should even drop the term Nature [as an efficient power], and should speak of these things as natural, even then it would be ridiculous to affirm at the same time that the parts of the whole are in their nature subject to change, and at the same time to be surprised or vexed as if something were happening contrary to nature, particularly as the dissolution of things is into those things of which each thing is composed.  For there is either a dispersion of the elements out of which everything has been compounded, or a change from the solid to the earthy and from the airy to the aerial, so that these parts are taken back into the universal reason, whether this at certain periods is consumed by fire or renewed by eternal changes.  And do not imagine that the solid and the airy part belong to thee from the time of generation.  For all this received its accretion only yesterday and the day before, as one may say, from the food and the air which is inspired.  This, then, which has received [the accretion], changes, not that which thy mother brought forth.  But suppose that this [which thy mother brought forth] implicates thee very much with that other part, which has the peculiar quality [of change], this is nothing in fact in the way of objection to what is said.[A]