DC-era punksters 9353 had a disc with the title We Are Absolutely Sure There Is No God, a beauty of a title right in line with many of their other album titles (UFO's Sideswiped Our Reform School Bus And That's Why We're Home Early, Mum). Inwardly, I came up with a joke variant, We Are Absolutely Sure There's No Future (as per the Sex Pistols).
One of the less palatable bits of Zen I came across early in my studies, but which makes far more sense now, goes something like this: the mind of the past, the present, and the future ("triple time", as they sometimes call it) are all unknowable. The past doesn't really exist because all you know of it is scavenged or reverse-engineered from evidence left behind. The present is only what you get through the tiny windows of your senses, which are limited and incomplete. The future is conjecture. To say that we "know" any of these things is not really accurate.
At first I hated this stuff because it sounded like pure defeatism. Later on, when I had a better understanding of the framing for all of it, it made more sense.
Nobody tells you "the mind of the past is unknowable" because they think studying history is meaningless, or "the mind of the future is unknowable" because attempting to make projections about future events is pointless. Or that "the mind of the present is unknowable" is an invocation to not bother noticing what's around you. These are all meant to be things you apply to yourself inwardly as ways of disciplining your own mind. You can go ahead and make plans for the future; just know that those plans were only made in this present moment, with all its own limitations. Feel free to find out what you can about the past; just remember, likewise, the past is only being appreciated through the lens of whatever fragments it let behind. And the present's like walking past a room where the door is only open a little bit: you see a sliding slit of a view into it, and you hear snatches of this and that, but don't kid yourself into thinking you have the whole picture.
The goal here, as I understand it, is a spiritual humility about what each one of us can truly know. Nowhere is it an attack on, say, science, or the ability for the human collective to advance itself through study of any of the above. In fact, it's in support of those things, because those are how we make each of our own individual myopias that much less myopic. Just that we can't ever confuse them with the Ultimate Truth Of Anything. And that we shouldn't let anyone else tell us these things as a way to use our humility against us, either; this is something we have to confront on our own, from within.
I worry a great deal about past, present, and future, because the "rational" side of me says there is a buttload of worry to be had about all three things. We don't learn from what the past left us; we don't pay attention to what's around us; and we don't think about what tomorrow brings. There are days when I wonder if this is it, if everything in my life is about to crash into the wall of tomorrow, head-on. Then I realize there's no way to know the answer to that except to see what tomorrow is.
When I was very young, I experienced a brush with death that even at that age I was aware had been a brush with death. A car ran me over, and I came within inches of being killed five different ways. Some time after I'd recovered from that, I remember thinking for the first time in my life, entirely on my own, "At some point I really am going to die, it's not going to be a near-miss like last time. What then?" And then I answered my own question: "I guess there's no way to find out but to go there. And that's something all of us do anyway." I wasn't so much worried about dying as I was worried about not being equipped for the experience — something the Tibetan Buddhists have a whole wing of their cultural museum, as it were, devoted to dealing with.
In The Open Society And Its Enemies, and in his earlier work The Poverty of Historicism, Karl Popper examined the idea of "oracular history" — of being able to divine the future of human society by reading the entrails of its past — and found it wanting. This was not the same as attempting to understand historical events analytically, but using what had come before as a prophetic example of what was to come later. He did not believe anything was inevitable, neither decay nor transcendence nor stasis. The same goes for any one of us as much as it goes for all of us, inasmuch as we are willing to do something about it.
Sometimes I think the hardest position to take for an intelligent person asked the question "What now?" is "I don't know." It runs the risk of making us look unintelligent. After all, anyone can say that, can't they? But it takes a special kind of humility to say "I don't know" in the right way — not out of mere ignorance or indifference, but out of caution. One does not want to tell others either a sweet or malicious lie. Maybe all one can do is explain why uncertainty and skepticism are the most honest, if least immediately satisfying, of answers to all questions.
The Korean Zen teacher Seung Sahn once told one of his students: nothing is certain, you could die in the next five minutes. Not to stimulate despair or resignation, but to get them to notice a little more clearly what was actually in front of them. If one was on the gallows with the noose around one's neck, wouldn't one want even ten more seconds to see and feel and hear? But again — not to disparage studying the past or considering the future. Only to know those things can only tell you so much about what's right in front of and inside you right here and now. That part is not something you can prepare for by reading about it or hearing other people talk about it — only by confronting it on your own absolutely personal terms.