How we cite our quotes: (Book.Chapter)
Quote #7
Every living organism is fulfilled when it follows the right path for its own nature. For a rational nature the right path is to withhold assent to anything false or obscure in the impressions made on the mind, to direct its impulses solely to social action, to reserve its desires and aversions to what lies in our power, and to welcome all that is assigned to it by universal nature. (8.7)
Marcus is big on following nature, since nature is the thing that defines your mind and your purpose in life. Because we're all given a rational mind, the goal is to live according to the precepts of reason. And the first rule of reason is to live life as a social being, working always for the common good. It's just an inescapable part of human identity, and one that must be accepted if we're is to live life in accordance with the plans of the universe.
Quote #8
But as things are you see how wearisome it is to live out of tune with your fellows, so that you say: 'Come quickly, death, or I too may forget myself.' (9.3.2)
Although everyone is given the same spark of divinity (reason), Marcus can't help feeling like the odd man out in his society. Perhaps it's because he's the emperor—that would certainly set him apart. It could also be because he's working hard to live a life according to principles that others don't value, or it could be because others have chosen to ignore their duty to live life in a rational manner. Either way, Marcus is having a hard time sticking to his philosophical regime in a world full of yahoos. He also fears that these fools may begin to change him (not for the better) before he can make it to the end of his life.
Quote #9
Remember that what pulls the strings is that part of us hidden inside: that is the power to act, that is the principle of life, that, one could say, is the man himself. (10.38)
Marcus talks about the rational soul here (which overlaps in many ways with the "directing mind") as the thing that gives life and purpose to our motion in the world. It's what we might simply call the soul these days—the vital power in us that we can't see or touch but that may endure separately from the body. It's also the thing that houses our personality—"the man himself"—the part that defines us as individuals. For all his talk about the commonality of human purpose and experience, Marcus is a strong believer in self-definition, without reference to the outside world.