Must sociology be qualitative?

This article addresses the question of whether sociology can in principle become a quantitative science. I distinguish several senses in which a contrast between quantitative and qualitative science might be understood. I focus on the central — and traditional — sense: can sociology become a nomological science, in the way physics is? I argue that it cannot, on the ontological ground that the determinants of human actions cannot be analyzed in purely causal terms. In the article I try to characterize this difference.