This book is as much history as it is philosophy - the story of how ideas shaped culture, the way culture then shaped ideas, and why we ended up thinking the way we do. It was published in 1945, so I suppose it was fairly important to Russell to figure out where ideas came from and why.
This approach is important to me because it seems that the passing of knowledge and culture is the most important thing in a given human's life. Imagine being born in the wilderness, with no knowledge of numbers or God -- this is where Russell begins in the history of human culture. It feels to me that I was born with an understanding that zero was an obvious concept. Perhaps more importantly, I feel I was born with the idea that social equality is the equivalent of justice. This surely wasn't so - there was a human who had to be the first to multiply, and another to recognize the passing of seasons.
Greygreywolfwolf recently said to me that "we are residing in the substance of other people's minds."
So, we start with the early Greek philosophers, who spent much of their time wondering whether the fundamental substance of life was air, or water, or fire, or earth, and finally concluding that it was all four. Another school held that there was a more fundamental building block -- atoms -- that composed all of matter. I don't know whether to be astounded that anybody without a microscope could even conceive of this, or to assume that even the first humans were considering this possibility. A similarly fantastic thing to me is the idea that stars are a great distance away. What could lead anybody to think that stars are millions of miles distant? Perhaps it took merely climbing a mountain and noting that their size had not changed at all. I don't know that I'll ever understand what any culture without a telescope thought of stars, and that saddens me. [Note: after writing this, I read passages later in the book that suggest most of our knowledge of space comes originally from lunar eclipses, which very clearly showed the Earth being round, and the moon being very far away. Sweet.]
At any rate, Russell says these earlier philosophers were "interested in everything -- meteors and eclipses, fishes and whirlwinds, religion and morality; with a penetrating intellect they combined the zest of children." It would be exciting to live in a time when scientific truths hadn't been so convincingly elicited. These days, it's very hard to think differently from physicists and astronomers. I think mostly of the declining biodiversity on earth, but the great dearth of ideas these days is saddening, too.
I am skirting the real issue I want to discuss, which is the handing down of ideas across generations. Plato lived about 25 centuries ago. If you assume an average of about five generations per century (Spartans, for example, did not have children until they were in their twenties, so I think that civilization has decided this the best decade to become a parent; we are, at any rate, only interested in a mean age of child-bearing). This means that there are 125 generations between you, the reader, and Plato. Only 125 parents have raised children since he discovered the awful possibility of the cave. I don't know if we can understand the passing of human time in any better way than thinking of generations -- my grandfather, for instance, knew people who fought in the Civil War. This makes the evolution of western ideas seem not so grand at all, but in fact rather short.
I want further to think about the difference between reality and memory, because I think such a gap exists not only for individual brains but for culture as well. Depending on the event, and the wisdown of a person, it may take many many years for her to decide the true meaning of the outcome. Why, we wonder, could this love not come to be? What did I learn from being 20 years old? Although we may never come to a single answer, we certainly narrow in on one, at which point the purpose of the experience was justified and we move on. The lesson becomes implicit. History, I believe, must behave similarly. Our cultural memory of the Civil War is essentially implict, whereas for my grandfather it must have been much more real.
Consider the State House in Lincoln, Nebraska. In the very top (the whole structure is 30 floors; it stands out like a dreamy temple-grain silo rising off the plains). There are mosaics dedicated to all aspects of human culture - agriculture, the arts, war. The war portrayed, however, is dedicated not to the First World War - which was being fought as the tiles were being affixed - but the Civil War. Such an affect that war had had on the country that fifty years later, it was still The War.
Still, the only way we can understand something is if we finally think it for ourselves - let another person reside in our own mind, or let us reside in theirs. Amazing that we are shaped by ideas 125 generations old.