In the last few decades, man's knowledge and understanding of his environment has increased at a prodigious rate. The great advances in science have brought with them three important consequences which must affect the teaching of physics. Firstly, there is a greatly increased demand for trained scientists; secondly, it is now desirable, perhaps even essential, for the average man and woman to have some idea of science; and thirdly, the sheer weight of new knowledge has now made it quite impossible for any course of instruction to cover the whole of any subject.