The process of acquiring knowledge passes through conspicuous changes in the educational practice. Also the theoretical study of this process is given much more attention than the process of making the knowledge acquired permanent. Permanency and solidity of knowledge as a condition of this usefulness is and index showing how close school is to life. Solid and permanent knowledge helps to understand new phenomena and their relationships, general laws governing natural and social phenomena, it helps to find the right answers to the complicated situations of everyday life. The usual ways of consolidating knowledge (exercises, revision, practical application) make it necessary and possible to differentiate the work quantitatively as well as qualitatively, in keeping with individual capabilities of the pupils. The new organisation of the lessons undoubtedly makes base phase of instruction more active. It will be necessary to book into the matter to find out to what extent it also promotes the consolidation and practical applicability of the knowledge and to what extent it helps to develop the pupils’ powers of independent reasoning and their capacity to learn new facts. f The process of rendering the knowledge solid and permanent cannot be reduced to mere drill during the lesson or to occasional revision. It requires a system in which each stage has its function, not only in itself but also in connection with other stages, from immediate drill to systemation and generalisation in the summing-up stage. The process of consolidating knowledge, being a significant component of the educational process, is in need of its innovators, theoreticians as well as practicians.