Abstract: The article is dedicated to the problem of the critical grounding of the formal logic (as well traditional as contemporary symbol logic) in phenomenological philosophy. The examples of such critical grounding of this discipline in E. Husserl and M. Heidegger are inquired here in more particularly way. The following theses are ascertained: Husserl believes that the logic is based on the constitutive activity of transcendental consciousness. And Heidegger thinks that logic has its in the human understanding of the being and therefore in the usage of copular verb in the sense of “presence-at-hand”. Moreover, the logic is read out from nature as domain, the being of which is the presence, and the logic’s application on the other domains of the being is its unjustified extrapolation in Heidegger’s opinion. And conclusion the question is put in the article, whether such phenomenological “destruction” of logic is only negation of it or a possible way to its grounding outside of the traditional shape of lo