For those of you who don't know the book, I would recommend it immensely. With Jeff Shore's Great Doubt, I think we practitioners have everything we need for our own practice.If we are to discuss this matter: It’s just like poling a boat upstream against the river current—you’ll go upriver [i.e., lift the huatou/the cue to full awareness] by one pole length, and you’ll fall back [i.e., produce deluded discrimination] by ten pole lengths. You’ll go up by ten pole lengths, and you’ll fall back by a hundred pole lengths. The more you pole, the more you’ll fall back—falling back over and over again. Even if you’ve fallen back to the very floor of the great ocean, take the prow of the boat and turn it back around—you absolutely, positively must keep poling up towards that. If you possess this kind of ambition and fortitude, then you will arrive at the home situation. As with people who go up a mountain, each one of them makes the effort on his own.
This matter, in fact, [deliberately] puts you into an antithetical position—just like that of a sumō fighter about to lock horns with his opponent. The moment you harbor even the slightest thought of fear—the moment you allow even the finest dust particle of discriminatory thought to linger within your mind—how will you avoid losing nine out of ten bouts? Even before contact has been made, your life will belong to the opponent. But if you have the iron-and-copper eye [i.e., the eye that sees right through everything], if you are filled with the fury that leaves you speechless, you will smash [your sumō pponent/your cue] to pieces in a single blow—in one single gulp. Suppose you lose your life [in the process, not just in the present birth but over and over again] for a thousand births and ten thousand aeons: you will never lose this mind-set. Practitioners! If you can in this way come to know your mistake [i.e., harboring fear and discriminatory thought], if you can in this way apply the whip [of zeal], there will be a specific day that you will achieve success and chop off [the sensation of ] indecision-and-apprehension. Strive on! Strive on!
I still don't know with Broughton chose to translate "doubt" as "indecision-and-apprehension", but it's an incredible resource. For those of you that don't know, this text spurred Hakuin's practice early on.