must philosophy and philosophical progress occur in the form of thinking?
Well, I think there are trivial non-thinking versions of this. Like, imagine you learn that there are advanced aliens somewhere nearby and you have an option to snoop on their internet.
You can advance human understanding of philosophy much more by snooping around their internet and lifting their philosophical arguments / concepts from there, than advance it by thinking yourself.
Other variants are like funding universities, having very smart kids with affordances to pursue philosophical research, etc.
Or, if you limit progress to my personal understanding of philosophy? Then I can just read stuff and get better than what I would have thought up myself. Same strategy, in some sense.
Those are baselines, to be fair. I’d expect there are much better, more philosophy specific approaches to this.
Well, if you are on the face on n-d cube, half of your neighborhood would be inside, no matter what n. But “most volume in the peel” is true of the n-d cubes too.