"[Messrs Ogden and Richards] will reply that they are considering the meaning of a "thought," not of a word. A "thought" is not a social phenomenon, like speech, and therefore does not have the two sides, active and passive, which can be distinguished in speech. I should urge, however, that all the reasons which led our authors to avoid introducing images in explaining meaning should have also led them to avoid introducing "thoughts." If a theory of meaning is to be fitted into natural science as they desire, it is necessary to define the meaning of words without introducing anything "mental" in the sense in which what is "mental" is not subject to the laws of physics. Therefore, for the same reasons for which I now hold that the meaning of words should be explained without introducing images – which I argued to be possible in the above-quoted passage – I also hold that meaning in general should be treated without introducing "thoughts," and should be regarded as a property of words considered as physical phenomena. Let us therefore amend their theory. They say: "'I am thinking of A' is the same thing as 'My thought is being caused by A.'" Let us substitute: "'I am speaking of A' is the same thing as 'My speech is being caused by A.'" Can this theory be true?"