Abstract
In order to clarify the concept of rationality, it is proposed to distinguish between the meaning of the word in a broad and narrow sense. Scientificity is understood as a fusion of rationality and logic. The science of modern times became possible after the abandonment of peripatetic ideals, focused on the search for final goal-setting, in favor of establishing an efficient cause. Science, based on classical rationality, studies and synthesizes only simple, mechanistic systems characterized by Laplace causality. Classical science perceives an empirical object in the form of a “black box”, functioning on the “stimulus - response” principle and is indifferent to both the nature and internal organization of the object of study. The transition of science to a non-classical type of rationality presupposes the involvement in the sphere of its interests of objects that have the form of a quantum of a complex system.