An interesting lecture and history lesson on what can happen when there is too much reliance on one person for scientific advice. Snow wants to point out the dangers of too much reliance from non-scientist policy makers on a single scientist, and, in general, how secret decisions are made by governments inevitably by a small number of people.
Snow uses a parable of Sir Henry Tizard and Lord Cherwell (Lindemann), where Tizard showed good instincts and judgments on how to allocate resources during WWII and Lindemann generally did not. The parable works fairly well, and is an interesting story in itself. It focuses on radar and strategic bombing.
Snow then explains the lessons, which are modest but I think the best that can be taken. Don't put too much faith in one expert. He also points out that because of science's increasing importance for policy decisions, it would be better to have more scientists or at the very least scientifically literate people in the government. This always sounds good in theory, but I am never as sure scientists would generally be good at policy, but Snow puts in the proper caveat that having more scientists would not necessarily lead to improvement, just that it may lead to more long-term thinking. Again, I'd agree that more scientific literacy is good, but I think it always just comes down to personalities and individual abilities. Indeed, this is another conclusion that Snow makes.
This was a good, quick read that lays out the problem for consideration and then examines some tentative answers. I'd recommend it to anyone who thinks about the proper relationship between government and science on policy, with especial regard to its handling of secret ("closed politics") research decisions.