A brief account of the development of quantum theory is made. Its roots can be almost entirely connected with the study of interaction of electromagnetic field with matter. From the start the assumption was that connection with classical theory should be severed, and new theory must be based on entirely new basis. In the recent studies quantum theory is formulated from classical, by adding a new postulate to the three Newton´s. On the example of angular momentum for a free particle it is shown how this approach gives entirely new view about its nature.