Much has been written on what "to mean" means. In taking up this issue within a limited sphere I will discuss it first — in order not to complicate my analysis — only with reference to the meanings of names of things, in particular of well-defined general names, or of terms, such as scientific and technical terms in the broad sense of the word: 'square", "house", "tree", etc. All approaches to the problem under consideration reflect three trends: (1) the psychological trend, according to which meaning is the content of thoughts about the designatum of a given name; (2) the behaviourist trend, which assumes that meaning is a disposition to a certain behaviour with respect to that designatum; (3) the semantic trend, which defines meaning in terms of the properties of the designatum. All three trends go beyond the sphere of logic.