The relations between innovations (= transformation of systems) and traditions (initial state of system) are determined in developing systems by particular role of feedback. The latter brings innovations into better agreement with the system structure and offers a considerable scope for their further development.
In the process of biological evolution the motive form of natural selection creates innovations in species formation on the wide probabilistic base (= biological coordinations). Stabilization form of selection that plays feedback’s role, preserves only those innovations, which are preassigned by the initial structure. In other words, innovations in question do not destroy species vitality (= morphological and topographical coordinations).
It is shown that in science history the principle of agreement plays the role of such a feedback between present state of science and it’s past. This principle confirms the agreement between new and old theories as the method of verification of new theory (classic mechanics as quantum mechanics for macroworld; invariability of species in C. Linnaeus’ scientific picture of the world as the base of classification in contemporary evolutional biology). The unity of innovations and traditions in developing systems could be considered as theoretical base of addressing to history of a science in order to solve its vital current problems and to widen and deepen the ethic base of its development.