It is one of the aims of linguistics to define itself, to recognise what belongs within its domain. In those cases where it relies upon psychology, it will do so indirectly, remaining independent.
Ferdinand de SaussureIt is useful to the historian, among others, to be able to see the commonest forms of different phenomena, whether phonetic, morphological or other, and how language lives, carries on and changes over time.
Ferdinand de SaussureOutside speech, the association that is made in the memory between words having something in common creates different groups, series, families, within which very diverse relations obtain but belonging to a single category: these are associative relations.
Ferdinand de Saussure