In this article I attempt to explain scientific revolutions with the help of economic concepts applying, in particular, concepts of the theory of com? petition. Scientists are seen as entrepreneurs, who take pains to maximize 'profits' by selling their 'products', e.g. new theories, textbooks, expert opinions etc. (I explain below what I mean by profit-maximization in this context). In this framework, a new theory can be interpreted as a product innovation, which for some time allows a monopoly profit to its inventor. After a while, however, other scientists will attempt to appropriate a share of this supra-normal profit. They can accomplish this by further devel? oping the theory, by writing new textbooks, by selling expert opinions that are theoretically 'up to date', and through other strategies. In this way, a school develops. Finally, however, the school becomes large and the 'prof? its' that a scientist can make by being a member of it are only 'normal'. That means that profits are on a competitive level. The theory has reached a state at which only marginal improvements are possible. An ambitious young scientist may already ask himself whether it is not more rewarding to 'invest' into a new promising theory, one which offers him greater opportunities for becoming famous. When this situation oc? curs, the theory in question has reached its maturity. Either it is left to itself as 'secured' or it is superseded by a new theory, that is, a 'scientific revolution' takes place. Ideas like these are certainly not new. Every scientific outsider who has witnessed the continuing growth of an adversary school, may have had similar thoughts. However, it suggests itself to proceed one step further and to apply economic theory to the incessant succession of scientific the? ories. This is, however, a daring step. One can hardly expect to be met with much enthusiasm by those who think of science as a noble quest for truth, unspoiled by low motives.