History: What has happened; science of what has happened.
If you want to know what human beings are, have been, and may be, in majority, minority and individually, you have to learn human history, if only to learn about the sort of mistakes that can be avoided, and how human beings behaved in fact, which is usually quite unlike their ideology makes them say or think they did.
The following are great historians who wrote great histories:
Thucydides: The Pelopponesian War.
Gibbon: The Decline and Fall of the Roman Empire.
Burckhardt: Kultur der Renaissance in Italien.
And this is a well-known adequate sum-up by a great historian and great writer:
"History is little else but the register of the crimes, follies and misfortunes of mankind" (Gibbon)
What makes a historian great is difficult to say, except that it is a combination of knowledge, style of writing, and personal judgment of the historian, for he must decide both what facts to present, and how to evaluate them.
An interesting 'potted history' is
John Carey Ed.: Eyewitness to History
that contains many brief selections from 'people who were mostly there when it happened'. This also happens to illustrate Gibbon's diagnosis, in a rather systematic way, since it concerns eyewitnesses reports from 2500 years of human history.
A useful observation about history and lesson from it, that also concerns plans for Utopia and more moderate attempts of trying to improve the world, is that so far nobody has been able to see as little as 25 years into the future: History shows that all expectations about the future have been mistaken, usually radically so. The history of humanity will be quite different from what it is expected - hoped, feared, guessed, predicted - to be, always excepting the confident expectation that it will be painful for many as long as human beings will be mostly as they have been through known history.
The main reason why history will probably be quite different from what it is expected to be is interesting, and tells something about human ingenuity and intelligence: What has radically upset all notions of what the future would bring is the progress of science and technology, that again and again introduced new ways of using nature, and of helping and harming humans.