The basic notions of "neoclassic" theory of cognition originated by V.V. Davydov - active nature of cognition, thinking act as a unit of cognition, thinking act criteria, types and forms of cognition, conditions and mechanism of thinking (ideal) acts' origins - are analyzed. The necessity of further theoretic development due to expansion of thinking act model, exposure of cognition mechanisms as its creation, apportionment and examination of cognition development stages is substantiated.