This paper intends to reason for the thesis of co-originality of truths (apophantic and hermeneutic truth) by deconstructing two prejudices: the logical one, according to which the enunciation is the "place" of truth and the phenomenological one, which says that the original truth is non-declarative.
The investigation of the co-presence of these two becomes possible by the introduction of the concept of truth as presupposition. As it has the nature of presupposition, it gains the nature of foundation. The presupposition of truth is not contained in language and therefore not to be found there; neither is it independent of language since it is, as pre-supposition, the condition of its possibility and endowment with sense. Therefore it makes explicit the phenomeno-logical structure of the Dasein and the necessity of rethinking the sense of understanding in terms of the co-originality of truths.
