One cannot think of any natural science in which orthodoxy swings between two poles. What gives economics the appearance of a science is that its propositions can be expressed mathematically by abstracting from many decisive characteristics of the real world.
&#160;经济模式的周期说明了经济学离一门科学的距离有多远。人们很难想象在任何一门自然科学中，正统说法会在两极之间摇摆。给予经济学它是一门科学的表象的东西是，它的命题可以通过提炼许多现实世界的决定性特征用数学加以表述。