The competition in modern jurisprudence of two respectable scientific disciplines: the philosophy of law and the theory of law, has so far reached such a poignancy that the relevance of the problem of demarcation of these concepts is beyond any doubt. Parallel with this, the question arises about their being-on-importance (ontological status) in relation to the legal reality, of which they are a reflection. Mr. Gadamer the first suggested using the term «valence» (Truth and method, 1959) to express this relationship. The paper considers the main approaches to solving this problem, among them three main ones are distinguished: quantitative, reflexive and phenomenological (existential). Each of these approaches has corresponding origins in t...