I spent a minute looking at the results of that phrase on ddg, and got a hit on the book in question. While it's not a direct quote, a search of the book finds

I spent a minute looking at the results of that phrase on ddg, and got a hit on the book in question. While it's not a direct quote, a search of the book finds this line: > On the one hand: We set limits to reason, preventing it from leaving the guiding-thread of empirical conditions and straying into the transcendent and explaining things in terms that can’t be cashed out empirically. And also, on the other hand (this being my present point): We set limits to the law of the purely empirical use of the understanding, preventing it from making decisions about the possibility of things in general—i.e. of things of any sort—and ruling that intelligible things are not merely incapable of explaining appearances but are impossible. I assume that's what OP meant.