Einstein was the first one who made it really clear and did away with certain unjustified assumptions concerning time that had been made without anyone being aware of it. This was a real philosophical achievement — the discovery of meaning by a logical clarification of a proposition. I could give more instances, but perhaps these two will be sufficient. We see that meaning and truth are linked together by the process of verification; but the first is found by mere reflection about possible circumstances in the world, while the second is decided by really discovering the existence or nonexistence of those circumstances. The reflection in the first case is the philosophic method of which Socrates' dialectical proceeding has afforded us the simplest example.
From what I have said so far it might seem that philosophy would simply have to be defined as the science of meaning, as, for example, astronomy is the science of the heavenly bodies, or zoology the science of animals, and that philosophy would be a science just as other sciences, only its subject would be different, namely, “Meaning.” This is the point of view taken in a very excellent book. “The Practice of Philosophy,” by Susanne K. Langer. The author has seen quite clearly that philosophy has to do with the pursuit of meaning, but she believes the pursuit of meaning can lead to a science, to “a set of true propositions” — for that is the correct interpretation of the term, science. Physics is nothing but a system of truths about physical bodies. Astronomy is a set of true propositions about the heavenly bodies, etc.
But philosophy is not a science in this sense. There can be no science of meaning, because there cannot be any set of true propositions about meaning. The reason for this is that in order to arrive at the meaning of a sentence or of a proposition we must go beyond propositions. For we cannot hope to explain the meaning of a proposition merely by presenting another proposition. When I ask somebody, “What is the meaning of this or that?” he must answer by a sentence that would try to describe the meaning. But he cannot ultimately succeed in this, for his answering sentence would be but another proposition and I would be perfectly justified in asking “What do you mean by this?” We would perhaps go on defining what he meant by using different words, and repeat his thought over and over again by using new sentences. I could always go on asking "But what does this new
