This article discusses the logic of non-stability, which claims to explicate the imaginary logic of Vasiliev. The statement “S is and, at the same time, is not P” acquires meaning 1, when the statement “S is P” changes its meaning on a minimal interval of a discreet scale. Such a non-stability of meaning is considered in two variants: in the usual, when meaning fluctuates from affirmation to negation; and in Vasiliev’s, when only the quality of a statement is changed. The main features of the logic of non-stability are presented. The syllogistics, where one or two premises are non-stable in some or other sense, is investigated. The correct modi are detected, and the correspondence between syllogisms with Vasiliev’s non-stability of the major premise with the results of Vasiliev himself.