[baddox]

That's irrelevant for two reasons. First, the life expactancy for someone who is x years old was higher than 38, which is the life expectancy at birth. Second, there's no obvious rule of nature that people will accomplish amazing feats at an earlier age if their life expectancy is lower.

[Crito]

Third: That was the life expectancy at birth across society in general at the time, not the life expectancy of somebody fortunate enough to be able to go into academia.

Most of the people mentioned in this thread from that era in fact lived into their 70s or 80s (70 for Leibniz, 84 for Newton, etc). That might be a coincidence, but I suspect that reduced occupational hazards played a significant role.