We often hear it said, for instance, "What is right in one age is wrong in another." This is quite reasonable, if it means that there is a fixed aim, and that certain methods attain at certain times and not at other times. If women, say, desire to be elegant, it may be that they are improved at one time by growing fatter and at another by growing thinner. But you cannot say that they are improved by ceasing to wish to be elegant and beginning to wish to be oblong. If the standard changes, how can there be improvement, which implies a standard?