In the XXth century naturalism and anti-naturalism, including the ideas of transcendentalism and a priori in Kant's sense, considered as a kind of conceptual antipodes, conceptual oppositions in relation to the antagonism of their methodological attitudes and principles. However, at the turn of the XXIth century, the intensive development of cognitive studies, accompanied by the expansion of the empirical base, pushed the need to revise the traditionally accepted incompatibility of naturalism and anti -naturalism. The article has the goal to assess the possibility of synthesis of naturalism and anti-naturalism in the context of the idea andmethodology of biocultural co-constructivism. Such a synthesis presupposes the rejection of biophobia, inherent for social science and humanities, the recognition of the heuristic significance of the idea of activity-type transcendentalism developing original Kantian ideas, as well as ascribing the ontological status to the previously considered a priori categories (the discovery of the brain's navigation system, neural networks responsible for the "sense of number", etc.). We claim that non-biological and non-genetic - social and cultural in their status - factors have a noticeable effect on the functions of neural structures, and the activity of various areas of the brain as a whole. The biological trajectory of the evolution of living creatures, which has traditionally been described in terms of naturalism, turns out to be closely intersecting with the socio-cultural trajectory of its development, previously described in terms of anti-naturalism. Therefore, a synthesis of naturalism and anti-naturalism is quite acceptable, which does not allow the concept of "naturalized apriorism" to be considered an oxymoron.
