If he is a stranger to the universe who does not know what is in it, no less is he a stranger who does not know what is going on in it. He is a runaway, who flies from social reason; he is blind, who shuts the eyes of the understanding; he is poor, who has need of another, and has not from himself all things which are useful for life. He is an abscess on the universe who withdraws and separates himself from the reason of our common nature through being displeased with the things which happen, for the same nature produces this, and has produced thee too: he is a piece rent asunder from the state, who tears his own soul from that of reasonable animals, which is one.
Judge every word and deed which are according to nature to be fit for thee; and be not diverted by the blame which follows from any people nor by their words, but if a thing is good to be done or said, do not consider it unworthy of thee. For those persons have their peculiar leading principle and follow their peculiar movement; which things do not thou regard, but go straight on, following thy own nature and the common nature; and the way of both is one.
Every nature is contented with itself when it goes on its way well; and a rational nature goes on its way well, when in its thoughts it assents to nothing false or uncertain, and when it directs its movements to social acts only, and when it confines its desires and aversions to the things which are in its power, and when it is satisfied with everything that is assigned to it by the common nature. For of this common nature every particular nature is a part, as the nature of the leaf is a part of the nature of the plant; except that in the plant the nature of the leaf is part of a nature which has not perception or reason, and is subject to be impeded; but the nature of man is part of a nature which is not subject to impediments, and is intelligent and just, since it gives to everything in equal portions and according to its worth, times, substance, cause (form), activity, and incident. But examine, not to discover that any one thing compared with any other single thing is equal in all respects, but by taking all the parts together of one thing and comparing them with all the parts together of another.
Nothing can happen to any man which is not a human accident, nor to an ox which is not according to the nature of an ox, nor to a vine which is not according to the nature of a vine, nor to a stone which is not proper to a stone. If then there happens to each thing both what is usual and natural, why shouldst thou complain? For the common nature brings nothing which may not be borne by thee.
All things which participate in anything which is common to them all move towards that which is of the same kind with themselves. Everything which is earthy turns towards the earth, everything which is liquid flows together, and everything which is of an aerial kind does the same, so that they require something to keep them asunder, and the application of force. Fire indeed moves upwards on account of the elemental fire, but it is so ready to be kindled together with all the fire which is here, that even every substance which is somewhat dry, is easily ignited, because there is less mingled with it of that which is a hindrance to ignition. Accordingly then everything also which participates in the common intelligent nature moves in like manner towards that which is of the same kind with itself, or moves even more.