Book VIII · Chapter 17

If a thing is in thy own power, why dost thou do it? but if it is in the power of another, whom dost thou blame,--the atoms [chance] or the gods? Both are foolish. Thou must blame nobody. For if thou canst, correct [that which is the cause]; but if thou canst not do this, correct at least the thing itself; but if thou canst not do even this, of what use is it to thee to find fault? for nothing should be done without a purpose.