While nothing about the genre or format of Marcus Aurelius's Meditations requires that there be any organization, Books II and III do some to have at least some integration of theme. We might summarize that of Book II with the phrase "Day by Day". We begin with a suggestion for morning reflection, a very Socratic reflection that no doubt had a great deal of significance for a Roman emperor: We will meet people doing all sorts of wrong because they do not understand good and evil, but the person who does understand good and evil cannot be harmed by them. We are all family, and thus it does no good to get angry at them:
We were born to labor together, like the feet, the hands, the eyes, and the rows of upper and lower teeth. To work against one another is therefore contrary to nature, and to be angry against a man or turn one's back on him is to work against him.
Pierre Hadot (The Inner Citadel, p. 264) notes that the book is pervaded by the theme of mortality. Death is possible today, and, even if it doesn't happen, the time one has is short. We must not waste our time with anything, even books, given that we have already delayed so much. Today is the day to act according to reason and nature; we must avoid being distracted and wandering from this.
The proper response to the recognition of our mortality is philosophy. Hadot has a good summary of the conception of philosophy involved in the book:
Only one thing counts: philosophy (II, 17,3), which consists of the three disciplines. First, it means keeping the guiding principle of the soul (hegemonikon; II,2,4), or--another way of expressing the same thing--the soul (II, 6) or else the inner daimon (II,17,4; II,13,2), free from the slavery of false thoughts (II,2,4). This is the discipline of thought or judgment. Second, the soul must be kept pure of all irritation against events, and accept the portion which has been attributed to it by destiny (II,2,4; II,16,1-2; II, 17,4); this is the discipline of desire. Finally, it must be kept pure of all egoistic action, or actions which are undertaken lightly or without a goal (II,2,4; II,17,4); this is the discipline of action. (p. 264)
Distractions of this world tend to take us away from philosophy, which is problematic because it is philosophy, this discipline of thought, desire, and action, that helps us to distinguish what is really real from what is merely our imagination or passional bias. Without it, we do not evaluate things as they really are, nor do we have any true sense of their place in the order of the world. Thus, for instance, we are constantly treating things as bogeyman that are, in fact, just the way the world works -- and to fear something that is just part of the natural order of the world is to be a child. Even death itself is precisely this sort of thing: a monster of the imagination that in reality is just a natural happening, and, what is more, a natural happening with any number of benefits for the world at large.
In addition, philosophy allows us to cultivate ourselves properly. Without it we are inclined to any number of forms of self-harm:
The human soul violates itself most of all when it becomes, as far as it can, a separate tumor or growth upon the universe; for to be discontented with anything that happens is to rebel against that Nature which embraces, in some part of itself, all other natures. The soul violates itself also whenever it turns away from a man and opposes him to do him harm, as do the souls of angry men; thirdly, whenever it is overcome by pleasure or pain; fourthly, whenever it acts a part and does or says anything falsely and hypocritically; fifthly, when it fails to direct any action or impulse to a goal, but acts at random, without purpose, whereas even the most trifling actions must be directed toward the end; and this end, for reasonable creatures, is to follow the reason and the law of the most honored commonwealth and constitution.
The most honored commonwealth and constitution, of course, is cosmopolis, the world as commonwealth. Everyone with reason, by virtue of their reason, is capable of acting as a citizen of the world itself; indeed, if we do not, we hurt ourselves. Through philosophy we avoid this, protecting our inner guide (daimon) and avoiding each of these five kinds of self-harm.
to be continued