Theoretical innovation is a form of creativity or scientific discovery. Therefore each innovation has to comply with the demands of novelty and theoretical value. Theoretical innovations, to the surprise of many philosophers of science, take place primarily at the intra-theoretical level, that is, in the context of a theory. The most common way to describe these innovations is as ‘predictions’, although there is a qualitative difference with the normal predictions that occur in the use of a particular theory. For the intra-theoretical innovations involve the incorporation into the theoretical stock of a novelty hitherto unknown. But the innovations or theoretical anticipations also occur at the inter-theoretical level making use of preducti...