The paper deals with the history of the expression ne mudrstvuja lukavo. Our task was to consider its origin and to study its semantic evolution over two centuries. First, we compare the system of meanings of the verb mudrstvovat’ and its synonym umstvovat’ in the modern language and in the language of the 19th century and investigate how the modern system of meanings was formed. We have found that the usage of the verb mudrstvovat’ is closely connected with the history of the idiomatic expression ne mudrstvuja lukavo. It has been generally believed that this expression was coined by Pushkin in “Boris Godunov”. Analyzing examples from 19th century texts we draw a number of arguments confirming this hypothesis. Then we try to determine the original meaning of this expression in Pushkin's text and compare it with its meaning in late 19thcentury teхts. Finally, we examine the semantic evolution of this expression in 20th century texts and come to the conclusion that one of its modern meanings is close to the original meaning in the 19th century.