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The only way to change behavior is through manipulation of reinforcement contingencies.

Investors should avoid trying to time the market; it's a losing strategy.

The greatest cruelty is our casual blindness to the despair of others.

——記者：你認為你是美國人還是中國人呢？

The speech we hear is an indication of that which we don't hear. It is a necessary avoidance, a violent, sly, anguished or mocking smokescreen which keeps the other in its place.

永遠不要低估一個想法改變世界的力量。

The essence of mathematics is not to make simple things complicated, but to make complicated things simple.