A single obscure decision of prophecy, perhaps the choice of one word over another, could change the entire aspect of the future. He tells us "The vision of time is broad, but when you pass through it, time becomes a narrow door.

He realized suddenly that it was one thing to see the past occupying the present, but the true test of prescience was to see the past in the future. Things persisted in not being what they seemed.

You never talk of likelihoods on Arrakis. You speak only of possibilities.

Religion often partakes of the myth of progress that shields us from the terrors of an uncertain future.

You can tell the future?'
'More like the future mugs me from time to time.' Rachel said
'I speak prophecies. The oracle spirit kind of hijacks me once in a while, and speaks important stuff that doesn't make any sense to anybody. But yeah, the prophecies tell the future.

In the computer field, the moment of truth is a running program; all else is prophecy.