I have staff members doing a PhD as part of the European Commission projects. Their undergraduate degree is in engineering and they are both brilliant, but because it is an interdisciplinary project, they are a little confused about the social science related aspects. We were talking a bit about the differences between the social sciences and other disciplines, and there is a line like this in the book "What is life?" I recommended earlier.
Mathematics is about perfection. Physics aims for the optimum. Biology, because of evolution, aims for a satisfactory answer".
What then of the social sciences? Perhaps it is in the social sciences that even satisfactory answers are difficult to find. In mathematics and physics, there are coherent theories that are difficult to overturn. In biology, everything from genetics to ecology is integrated on the basis of Darwin's theory of evolution. Economics is based on the rationality of maximising utility, but there is no unified theory in the other social sciences. It is unlikely that any single theory will be used to study the farmer-grocers and the urban poor.
Despite this unsatisfying feeling of bewilderment, the social sciences have not given up on the idea of "to know" in the original Latin meaning of science.
So I think of social science as a discipline that continues to search for answers.
Recently, physicists have been using physical theory to analyse problems in the social sciences, in biology and in the social sciences. I recommend this book, Critical Mass, which summarises the story in an accessible way. I'll see if I get a chance to write another review on this book!