The most important work of the outstanding French materialist and atheist Helvetius K.A. "On the mind" is devoted to criticism of the feudal social system, idealism and religion. In the book "On Mind," Helvetius expounds his sensualistic theory of knowledge and tries to build on its basis a socio-political and ethical teaching that reflects the interests and demands of the revolutionary French bourgeoisie of the 18th century. The book of Helvetius is a vivid example of talented and witty atheistic literature of the 18th century.