You could also represent it this way:
Psychology and Chess

Fischer said himself, "I don't believe in psychology. I believe in good moves".
Fischer didn't mean psychology. Fischer meant to say cheap tricks.
People that have an IQ over 180+ like Fisher make such statements at times and it does not mean that they are right, but think about what he really said.
He is saying , I think, that he believes in psychology and denies it to simply have any and all opponents think that only moves are important thereby foregoing a strong tactical approach called psychology, he wants to be the first one to use it in any game and following is astute psy application he has ann edge.
I couldn't understand your second sentence.

I suspect what he meant is that perfect play will beat psychological tactics every time, and in that sense he would be correct.

I have seen some opponents (immature people) trying to play with a psychological touch... sometimes it works... sometimes they just act like JERKS.
Fischer said himself, "I don't believe in psychology. I believe in good moves".
Fischer didn't mean psychology. Fischer meant to say cheap tricks.
Did he ? I think Fischer understood what 'psychology' meant.
I've played with that idea.
Not sure I'm settled on which stamp to use for the knights.