We are all working together to one end, some with knowledge and design, and others without knowing what they do; as men also when they are asleep, of whom it is Heraclitus, I think, who says that they are labourers and cooperators in the things which take place in the universe. But men cooperate after different fashions: and even those cooperate abundantly, who find fault with what happens and those who try to oppose it and to hinder it; for the universe had need even of such men as these. It remains then for thee to understand among what kind of workmen thou placest thyself; for he who rules all things will certainly make a right use of thee, and he will receive thee among some part of the cooperators and of those whose labours conduce to one end. But be not thou such a part as the mean and ridiculous verse in the play, which Chrysippus speaks of. 51

Does the sun undertake to do the work of the rain, or Æsculapius the work of the Fruit-bearer [the earth]? And how is it with respect to each of the stars, are they not different and yet they work together to the same end?