2. A right joining or separating of signs, i.e., either ideas or words.
Truth, then, seems to me, in the proper import
of the word, to signify nothing but the joining or separating of Signs, as the Things signified by them do agree or
disagree one with another. The joining or separating of signs here meant, is what by another name we call
proposition. So that truth properly belongs only to propositions: whereof there are two sorts, viz., mental and
verbal; as there are two sorts of signs commonly made use of, viz., ideas and words.