Meditations 10.26

A man deposits seed in a womb and goes away, and then another cause takes it and labors on it, and makes a child. What a thing from such a material! Again, the child passes food down through the throat, and then another cause takes it and makes perception and motion, and in fine, life and strength and other things; how many and how strange! Observe then the things which are produced in such a hidden way, and see the power, just as we see the power which carries things downwards and upwards, not with the eyes, but still no less plainly.

Marcus Aurelius, Meditations 10.26, translated by George Long

A man passes seed into a womb and goes his way, and anon another cause takes it in hand and works upon it and perfects a babe—what a consummation from what a beginning! Again he passes food down the throat, and anon another cause taking up the work creates sensation and impulse and in fine, life and strength and other things how many and how mysterious! Muse then on these things that are done in such secrecy, and detect the efficient force, just as we detect the descensive and the ascensive none the less clearly that it is not with our eyes.

Marcus Aurelius, Meditations 10.26, translated by C. R. Haines