In that paragraph, I was trying to argue that the observation of us being alone and the anthropic principle are compatible and related in a way that if either o

In that paragraph, I was trying to argue that the observation of us being alone and the anthropic principle are compatible and related in a way that if either one were missing, we should be skeptical of the other. I think that's valid and distinct from a circular argument. (And then in the last paragraph, I wasn't trying to argue for the anthropic principle, but to argue that given the anthropic principle and the observation we're alone, then I think it's correct to believe that the specific values of physical constants that we observe are likely to be necessary for intelligent life.)