Discourses: Book 3 26 : 3
Ought you not, first, to have acquired something from reason, and then to have made that something secure? Why, did you ever see anyone building a cornice all around without first having a wall about which to build it? And what kind of doorkeeper is placed on guard where there isn't any door? But you practise to get the power to demonstrate; demonstrate what? You practise to avoid being shaken by sophisms; shaken from what? Show me first what you are maintaining, what you are measuring, or what you are weighing: and after that, and under those conditions, show me your scales or your bushel-measure. Or how long will you keep measuring ashes? Are not these what you ought to be demonstrating, the things, namely, that make men happy, that make their affairs prosper for them as they desire, that make it unnecessary for them to blame anybody, and to find fault with anybody, but to acquiesce in the government of the universe? Show me these. "See, I do show you," a man says; "I will analyse syllogisms for you." Slave, this is a mere measuring instrument, it is not the thing measured. That is why you are now being punished for what you neglected; you tremble, lie awake, take counsel with everyone, and, if your plans are not likely to win the approval of all men, you think that your deliberations have been faulty.