It is said that "like attracts like," and also that like repels like. Instances of both are found in science: if a solution of two or three different salts, is left to crystallize, the particles of each salt will congregate together. On the other hand, the like poles of a magnet will repel each other.
The trouble arises from the use of an undefined word, the word "like." A woman is like a man in the sense that both are human as contrasted with animal or vegetable. But if we are thinking of humanity alone, we can describe the woman as a polar opposite of man. Therefore man and woman are at the same time like and unlike each other. Birds of a feather flock together, says the proverb; and that is because like attracts like; but all the same there may be a terrible scrap if two male mocking-birds should happen to meet in the mating season. This is because like repels like.
This is just one example of the way in which people arguing may get a temperature, all because they are using undefined words, or students may find what they call contradictions in teachings. We have to learn to think in thoughts, not in words; and to detach words from ideas; also not to let
ourselves be hypnotized by proverbial expressions.