The moral sciences are those specifically concerned with the human spirit. In this lecture we'll examine the methodology of these sciences, of which there are four kinds: philosophy, social science, philology, and history. At the beginning of this course, we discussed the method appropriate for philosophy. Now we'll examine the methodology of the social sciences.

There are three kinds of social sciences: politics, law, and political economy.

Politics is the science of society, and its aim is to determine the best form for human society to take. What's the method of politics? It's often been approached in a kind of geometrical manner, as in, for example, Plato's Republic. But today this method has been abandoned and replaced by observation and experimentation, with history providing the facts.

Law, by contrast, concerns itself with legal rules and tries to determine – by deduction alone – how these rules apply in concrete cases.

Political economy used to be approached in the same way as politics, by studying in an abstract way the relationships between various human interests.

But this method too has been abandoned today. Political economists now study how these relationships play out in the present as well as in historical experience. Reasoning still plays an important part in what they do, but political economy is now richer because it attends to new facts made available through observation and experience.

The philological sciences study the laws of language – whether those of one particular language, a group of languages, or all known languages.