A critique of treatments of presupposition in the literature, an attempt to settle the notion, and to explain its relationship with allegation. Presuppositions are said to be connected with the morphemic structure (or semantic features such as 'factive' etc.) or with an element belonging to the contextually bound segment of the sentence; an allegation is entailed only by a sentence where the element determining it is not in the scope of negation; meaning proper (i.e. assertion) consists in the relationship between what is talked about and what is said about it.