Jeremy Stangroom

But the failure of one person (however prominent) is not similar to the failure of most people who subscribe to a moral system.

So, for example, Bertie Russell, who advocated for free love, but was unable to handle the free love of his second wife, Dora. I think that does tell you something about the problems of free love, not as a matter of logical necessity, but even so...

I agree when that is based on observation of many people (and I agree that there’s such evidence in this case). I disagree that just Russell’s example is informative. Consider two hypothetical examples: 1/

A: an anti-child-molesting crusader turns out to be a child molester. B: an anti-homosexuality crusader turns out to be gay. While we may consider both of them hypocrites, I don’t see why their stories would inform our opinions on principles they represent. 2/

I would say A stood for the right principle and B stood for the wrong principle, whether I knew what they personally did or not. That A is a criminal and B merely a hypocrite certainly doesn’t undermine A’s principle more than B’s. 3/3

Hang on a minute, you're talking about principles qua principles, but my response was - "The failure of somebody to live up to their own moral system can certainly be evidence against *the theory of human nature* upon which the system is built."

And I was taking seriously both the words *can* & the idea of evidence rather than logical necessity. Bertrand Russell's failure doesn't tell you anything abt the principles underpinning free love, except it suggests, given what we know about his life, they're hard to live up to.

If your response is that one person's life can't tell us anything about that sort of thing - I think that's not right. We can know enough about a person's life to make a judgement about whether they're likely to be psychological outliers.