> Natural selection is essentilly “survival of the fittest,” so long as “fitness” means the reproductive success of a genotype (and I suppose also with the implicit understanding that parlaying “survival of the fittest” into a “survival of the fittest”

I thought... Natural selection was a process which resulted in 'survival of the fittest' sure, but the process was spelled out both in a natural language (3 or controversially 4 clauses on variation, heritability, mutation, and arguably differential fitness) and also in the math (which i'll leave to you).

I had a psych lecturer who said it was unfortunate that people talked about 'survival of the fittest' as it was (according to him) more about 'elimination of the unsuccessful'. As you pointed out just because something is alive doesn't mean it is perfectly adapted, it just means that nothing has killed it.

I do have sympathy for the circularity idea, however. Sometimes I think that explanation is just one big circle really and an ideal explanation just makes the circle so big that it is hard for beings with tiny little finite brains like ours to grasp it in one fell swoop. For instance...

(I don't think we have sympathy for the reductionist program but lets humour them and see where it gets us)

Mind can be reduced to Psychology
Psychology can be reduced to Biology
Biology can be reduced to Chemistry
Chemistry can be reduced to Physics
Physics requires an observer
Which brings us back to Mind.
;-)