Aurelius, Meditations §aur_08_x: This, what is it in itself, and by itself, according to its proper constitution?

This, what is it in itself, and by itself, according to its proper constitution? What is the substance of it? What is the matter, or proper use? What is the form or efficient cause? What is it for in this world, and how long will it abide? Thus must thou examine all things, that present themselves unto thee.