What is a good procedure for determining whether someone has good judgment? Is it never making an investment in a person or company that turns out wrong? Then those who never invest at all have the best judgment. But that can't be right.

I think good judgment is shown by those whose investments (of money, time, trust, reputation, or anything) turn out to be better than those in their class. By this measure, Thiel has shown good judgment - his investments of money, time and trust have turned out unusually positively overall. It's been...colorful, at times, but unusually positive overall.

To show someone has poor judgment, one would need to point to a pattern of poor decisions, preferably some hard metric (like investment returns). A single instance of misplaced trust seems inadequate. Does Thiel trusting Elon Musk cancel out his (probably delegated) trust in that Thiel Fellow? I think it does and much more.

Just read through all 3 posts in the history of this incident, and I am dumbfounded.

It reminds me of how I was friends with a con-artist in college and had no idea about it (though I did think he had compulsive lying disorder).

I genuinely wonder what sort of heuristics Thiel used, and why his presumably quite reasonable approach failed to catch this anomaly.