Here is a brief overview of sociology that is not for children or undergraduates but for adults who still confuse it with statistics, which is one of the methods used in sociology, and with anthropology, which studies pre-literate cultures and addresses modern cultures only to the extent that they are like pre-literate cultures.

The basic insight of sociology is that relationships, even if invisible, are just as real as atoms or people. Friendship is as old as Achilles and Patroclus, or David and Jonathan, and, if Radcliffe-Brown is right, exists in pre-literate societies, where friends also kid around with one another. The characteristics of friendship, such as trust and respect, remain constant over time even if other characteristics, such as whether people who are social unequals can be friends, either change or simply come to be thought about differently over time. The same can be said of other relationships. A general who wears a toga, as Alcibiades did, is doing the same thing as a general wearing an Ike jacket: deploying troops to go into battle and perhaps die there. What applies to individuals also applies to larger units of social life. Whether a city state or a nation state, governments will do whatever it takes to uphold the interests of their communities whatever they see them to be  and whatever measures that may require. George Marshall said that the best primer on government and war was Thucydides’ The Peloponnesian War. The impact of immigration on a society has not changed since the Israelites invaded Canaan: there are fights over religion and land. Sometimes, though, overall characteristics have to be modified to deal with particular circumstances. For some reason, immigrants to the United States assimilate in the space of several generations while immigrants to Continental Europe do not.