Professor Robert Solow is one of the most distinguished and prestigious economists of our time. He is a calm and confident scholar with rare mastery of the technical tools of economic and quantitative analysis. To the extent that economics qualifies as a science, it is men like Professor Solow who have earned it the reputation. The rather subjective standards of the social sciences in general and of economic theory in particular allow men a certain liberty in defining their own competence. A scholar is often what he claims to be. But Professor Solow’s superior mastery of his discipline is acknowledged and admired I think by all.