It is impossible to assert the identity of meaning of two expressions. For in order to be able to assert anything about their meaning, I must know their meaning, and I cannot know their meaning without knowing whether what they mean is the same or different. An equation merely marks the point of view from which I consider the two expressions: it marks their equivalence in meaning. The question whether intuition is needed for the solution of mathematical problems must be given the answer that in this case language itself provides the necessary intuition. We do not have an a priori belief in a law of conservation, but rather a priori knowledge of the possibility of a logical form. Stuff and things Menu My Torah Logic meaning, I must know their meaning, and I cannot know their meaning without knowing whether what they mean is the same or different. An equation merely marks the point of view from which I consider the two expressions: it marks their equivalence in meaning. The question whether intuition is needed for the solution of mathematical problems must be given the answer that in this case language itself provides the necessary intuition. We do not have an a priori belief in a law of conservation, but rather a priori knowledge of the possibility of a logical form.