Consider the following:
Taken from WWWJDIC's example sentence database:
History is a branch of the humanities.
The study of philosophy belongs to the humanities.
That university's curriculum covers natural science and social science.
社会科学 would correspond to
social science respectively.
Now the question becomes "What is the difference between humanities and social sciences?"
To quote from this article:
Humanities are a branch of science that deals with the heritage and the question of what makes us human. Humanities deal with law, history, ancient languages, modern languages, philosophy, history, religion, and visual/performing arts. Humanities are considered to be more philosophical than social sciences.
As there is a scientific approach to social sciences, it is considered to be a branch of study in between humanities and natural sciences. Anthropology, criminology, administration, archaeology, education, economics, psychology, linguistics, political science, law, and history come under the purview of social sciences.
There is some overlap between humanities and social sciences, but the difference lies in the approach.