While the individual man is an insoluble puzzle, in the aggregate he becomes a mathematical certainty. You can, for example, never foretell what any one man will be up to, but you can say with precision what an average number will be up to. Individuals vary, but percentages remain constant. So says the statistician.
Pay no heed to the average photographer's remarks upon "flat" and "weak" negatives. Probably he is flat, weak, stale, and unprofitable; your negative may be first-rate, and probably is if he does not approve of it.
The voyage of the best ship is a zigzag line of a hundred tacks. See the line from a sufficient distance and it straightens itself to the average tendency.
Laws, religions, creeds, and systems of ethics, instead of making society better than its best unit, make it worse than its average unit, because they are never up to date.
Whenever the average intellect of the clergy declines in the balance with the average intellect of the people the churches will be shut up and a new order of things [will] begin.
The extraordinary woman depends on the ordinary woman. It is only when we know what were the conditions of the average woman's life - the number of children, whether she had money of her own, if she had a room to herself, whether she had help bringing up her family, if she had servants, whether part of the housework was her task - it is only when we can measure the way of life and experience made possible to the ordinary woman that we can account for the success or failure of the extraordinary woman as a writer.
When the highest type of people hear Tao (Truth), they diligently practice it. When the average type of people hear Tao, they half believe in it. When the lowest type of people hear Tao, they laugh at it. If they did not laugh, it would not be Tao.
The optimum portfolio depends on the various expectations of choices available and the degree of variance in performance which is tolerable. The greater the number of selections, the less will be the average year-to-year variation in actual versus expected results. Also, the lower will be the expected results, assuming different choices have different expectations of performance.