The article stems from 1960. Compare this citation with the causes of the Chernobyl disaster:
"The probabilistic nature of the "laws of nature" manifests itself in the case of machines also, and can be verified, at least in the case of nuclear reactors, if one runs them at very low power."
Awesome. A lot of people revile Steve Sailer, but I think he's one of the best essayists writing today.
This quote in particular elegantly sums up the history of philosophy:
"To this day, most philosophers suffer from Plato's disease: the assumption that reality fundamentally consists of abstract essences best described by words or geometry. (In truth, reality is largely a probabilistic affair best described by statistics.)"
It's not so much the world that's probabilistic, though, as the human mind and the thoughts and abstractions we impose on the world. Hume was the first philosopher to explicitly argue that the mind works this way, and modern research has supported him.
I think that, as Sailer briefly suggests, there is value in studying the works of skeptical philosophers like Hume: it gives you the tools to see through the kind of bullshit that philosophy is full of. Because you don't just see it in philosophy. It's there whenever people argue about politics or religion, and whenever a dreamy computer scientist rambles about "objects" and "types" and whatnot. It's useful to able to refute these arguments by recognizing their meaninglessness.
I only revile Steve Sailer because of his self-marketing campaign of leaving many tiresome comments on the Freakonomics and Malcolm Gladwell blogs, taking the authors to task at length over various issues. I was unaware he was well-known from anywhere else. His essays may be splendid but he behaves like a kook.
The world is fundamentally probabilistic, though (see quantum mechanics). If anything, it is the human mind's ideas that are not probabilistic in a similar fashion, or at least that remains to be proven.
Before Plato and Heraclitus, Greeks thought reality was essentially chaotic and impossible to understand. You can see this in their creation myths. Heraclitus originated the idea of the Logos, a pattern underlying everything, and Plato built on this.
Articles like Steve's happen when people don't know their history of philosophy or science.
The thing about philosophy is that it ultimately questions everything and is the gateway to every new realm of knowledge. Useless philosophy is just stagnant thinking that has given up on truth.
Better to read 'The Unreasonable Effectiveness of Mathematics in the Natural Sciences': http://euler.slu.edu/~srivastava/wigner.pdf