This is one of his main points and it's a very important one.
I watched 2001: A Space Odyssey again last night and, since it's been probably 20 years since the last time, I was struck by how far we've fallen and how pathetic we've become as a people.
We no longer strive to achieve great things, we just grub around looking for fictitious symbols of debt as if they are of any substance. Sure, we got out of our gravity well for a minute and we littered the moon a little, but Clark wrote his book by looking at how far we advanced in the forty-some prior years and extrapolating that same pace forty-some years into the future.
My great grandmother (1881 - 1980) was born in a sod house with a hand-pumped well and an outhouse and saw the advent of electricity, flight, workers rights, womens suffrage, space flight, the civil rights act, networks of paved roads, skyscrapers, cars, computers, the double helix, fatal diseases eradicated, the ability to produce enough food to end hunger, telephones, refrigeration, moving pictures, talkies, unions, radio, television, atomic power, sewing machines, vacuum cleaners, and a thousand other things we don't even imagine living without.
Do you think any of us will see anything that even approaches that kind of progress? I'm at least half done with my life and the greatest advances I've seen are computer networks and propaganda being elevated to a science.