Probably not what you're after, but there's Making Rationality General-Interest by Swimmer963. Further out but with a little overlap with what you describe: Of Gender and Rationality by Eliezer. Or No Safe Defense, Not Even Science by Eliezer.

I think it's less than 25% probable that any of these is what you're after, but (1) looking at them might sharpen your recollection of what you are after, (2) one or more might be a usable substitute for whatever your purpose is, and (3) others reading your comment and wanting to help now needn't check those :-).