Just came across a great quote on William of Ockham made by Mike Flynn, himself commenting a post by Edward Feser (thus introducing me to a great blog I wish I would have come across long before!). Anyway, here is Michael Flynn's comments, adding to Edward Feser's thoughts:
Christopher Hitchens claims that William undermined medieval scholastic thought using proto-scientific rationalism. But because it is Hitchens, we know that it must be wrong. In fact, William was a voluntarist who believed in the Triumph of the Will, specifically of God's Will. This was contrary to Thomist thinking, which held that the intellect was prior to the will. (Basically, you cannot desire something that you do not know.) As always when you get things exactly bass-ackward, things do not cohere and all sorts of "paradoxes" and "problems" appear out of nowhere. Causation blows up, and with it ethics and morality, and the limited state. There is no demonstrable connection between cause and effect, so causation goes bye-bye; and it is only so far as scientists paid little attention in practice to Ockhamism/Humeanism that science prospered at all. When al-Ghazali pulled the same stunt in the House of Submission, the scattered fires of natural science faded out. The triumph of the will over the intellect meant that God becomes the Tyrant in the Sky issuing arbitrary rules about what is good or bad. Draw a straight line from there to absolute monarchs and libertarians. (A libertarian is an absolute monarch with a very small kingdom.) The denial of essences meant that you could never know if another creature was "really" human. If there was no human "nature" or "essence," then there are only individual human beings; and those creatures with different skin colors or talking jibber-jabber might not be human at all.
Unfortunately, we all know where that led...