Steven Pinker has been
getting much attention lately for arguing in his new book

The Better Angels of Our Nature, against a lot of people’s
surface assumptions based on a pretty geopolitically violent past
century, that modernity and the modern state have in fact made the
world a far less violent place. 

David Bentley Hart at First Things
wonders if Pinker’s measures make the most sense, given that we
are still, after all, sitting on a pretty big pile of murdered
bodies here in the aftermath of the 20th century:

Pinker’s method for assessing the relative ferocity of different
centuries is to calculate the total of violent deaths not as an
absolute quantity, but as a percentage of global population. But
statistical comparisons like that are notoriously vacuous.
Population sample sizes can vary by billions, but a single life
remains a static sum, so the smaller the sample the larger the
percentage each life represents. Obviously, though, a remote Inuit
village of one hundred souls where someone gets killed in a
fistfight is not twice as violent as a nation of 200 million that
exterminates one million of its citizens. And even where the orders
of magnitude are not quite so divergent, comparison on a global
scale is useless, especially since over the past century modern
medicine has reduced infant mortality and radically extended life
spans nearly everywhere (meaning, for one thing, there are now far
more persons too young or too old to fight). So Pinker’s assertion
that a person would be thirty-five times more likely to be murdered
in the Middle Ages than now is empirically meaningless.

In the end, what Pinker calls a “decline of violence” in
modernity actually has been, in real body counts, a continual and
extravagant increase in violence that has been outstripped by an
even more exorbitant demographic explosion. 

A Reason.tv inteview with Pinker: