Meditations, Book 8, Section 6

Marcus Aurelius — The Emperor

A leaf is part of the common nature of all plants and trees. But a leaf's nature is part of something without reason or feeling. It can be blocked from its purpose. It is bound and limited. But human nature is part of a common nature that cannot be stopped. This nature is both reasonable and just. This is why it gives fair shares to all things - time, substance, form, action, events, and accidents. It distributes according to what each thing deserves. But don't look for this fairness in each single thing by itself. Look at all the parts of one thing together, compared with all the parts of another thing together.

Marcus Aurelius — The Emperor Original

For it is part of it; even as the nature of any one leaf, is part of the common nature of all plants and trees. But that the nature of a leaf, is part of a nature both unreasonable and unsensible, and which in its proper end may be hindered; or, which is servile and slavish: whereas the nature of man is part of a common nature which cannot be hindered, and which is both reasonable and just. From whence also it is, that according to the worth of everything, she doth make such equal distribution of all things, as of duration, substance form, operation, and of events and accidents. But herein consider not whether thou shalt find this equality in everything absolutely and by itself; but whether in all the particulars of some one thing taken together, and compared with all the particulars of some other thing, and them together likewise.