SO WHY BOTHER WITH SOCIAL SCIENCE? Having said all that–if social science rests on philosophy, why not just present the philosophical case? Well, there are three basic reasons that I can think of: 1) People may share enough of your premises and assumptions that social-science research will actually convince them of your conclusions. For example, if you accept the ways John Lott gathers and presents his “more guns, less crime” numbers, you may well go from a generally pro-gun control position to a generally pro-concealed carry position. (Lott says he himself made that journey over the course of his research.) You agree more with the various statistical methods and comparisons Lott uses than you do with your gun-control beliefs (and you agree that such stats are relevant to gun policy), and so when they conflict, you ditch the gun control. Another example would be stats showing the percentage of people on Death Row who were later found innocent, or the percentage who have mental disabilities, or the percentage who were convicted of killing white victims as vs. black victims (all other circumstances being as equal as can be reasonably expected–which will vary based on your assumptions about what counts as “more or less the same”)–these numbers do matter to people, if they can be accurately gathered, because many people share premises that would lead to different conclusions if these numbers go up or down.
2) Social science, when conducted carefully, can tell us about what people do, and that’s a necessary part of building up a picture of human nature. It can never be the whole, of course. But soc-sci conclusions can help us refine our views of human nature. An unexpected conclusion may startle us–especially if we can’t find an explanatory flaw in the methodology. That experience of being startled is analogous to the experience of being startled by something you do personally, or something done by someone you know; in all three cases, you’re being startled because your views of what human beings are like, how we operate, have been challenged. Soc-sci gains in persuasive heft because it involves more people than your own experience does; but it loses persuasive heft because you are less likely to be startled by it unless you have already been prepared to accept its premises and assumptions. So all in all, soc-sci can be one among many arrows in the quiver of people seeking to learn about human nature.
3) Philosophy and experience correct and challenge one another. There’s no straight line, in which, before you can have an opinion on anything, you need to first identify all your premises, and you hold onto those premises until you die. Just as philosophy can color how you interpret your experience (or drastically change your interpretation of your life!), so experience can lead you to rethink your philosophy. Soc-sci research is a strange mixture of experience and philosophy, and often that mixture isn’t handled very well, but it’s not inherently impossible to do good soc-sci research.
Final thought: In many ways, all attempts to “learn from history” and to argue by historical analogy require the same kinds of premises and assumptions that soc-sci research requires. People seeking to learn from history are essentially treating history as a big soc-sci experiment or study–encompassing more variables than any such study could encompass, of course, but for that reason much more chaotic. If looking to history is an acceptable guide for policy, then it seems looking to social science should be an acceptable guide as well–although in both cases, it’s wildly easy to make bad jugdments and do sloppy argumentation.