"Is the future written?" bundles three different questions—is it real, is it fixed, is it knowable—and separating them shows that even a real, fixed future would not be a fated one, because it is unknowable in advance and gets written through your choices.
Is it real? On the block-universe reading of relativity, future events are as real as present ones—there is no privileged moving "now" that alone exists—so in that sense the future already "is".
But reality is not the same as fixity: an event can be real at its own time and still be causally undetermined by earlier states.
Is it fixed by the present? Here the physics is unsettled. Classical determinism says the present state plus the laws fix a unique future; but quantum mechanics, on most interpretations, includes genuine chance—the present fixes only probabilities for many outcomes—so the future may not be uniquely written by the past.
Either way, note what determinism does not imply: even if the future is fixed, it is fixed partly by your deliberations, which are themselves links in the causal chain, so "fixed" does not mean "settled regardless of what you do".
Is it knowable? No—and this is the practically decisive point. Whether or not the future is determined, it is radically unpredictable: chaotic sensitivity, computational limits, and (if quantum chance is real) irreducible randomness make it unknowable in advance to any agent within the world.
So from the inside, the future is open in every way that bears on how you act.
The upshot: don't let "the future may be real or fixed" collapse into fatalism—the classic error of concluding "so my choices don't matter." They do, because your choosing is the mechanism through which the future is determined, and it is unknowable until you make it.
Deliberate and act as though it is open, because relative to you it is. This would shift only if reliable foreknowledge of specific future choices were demonstrated—none has been.
It depends what "written" means—and untangling that dissolves the fatalism the question usually smuggles in. Ask three separate things: is the future real, is it fixed, is it knowable. The answers differ, and only the last one matters for how you live.
Quickly:
That last point is the whole practical game. The trap is going from "the future might be determined" to "so nothing I do matters"—and that's just a logical error. Determinism doesn't mean your choices are bypassed; it means your choices are how the future gets determined. Fatalism ("what will be, will be, regardless") is false even in a fully deterministic world, because the "what will be" runs straight through what you decide.
So: don't confuse fixed with futile. Whether or not the future is written in some cosmic sense, it is unwritten to you—unknowable until you act, and shaped by the acting. Deliberate, choose, and work as though it's open, because from the only vantage you'll ever have, it is. The pen, in every sense that touches your life, is in your hand.
The Book and the Writing.
Two images fight for the future. In one, it is a book already written, every page bound, the ending fixed before you turn to it—and you merely read your life aloud, discovering what was always there. In the other, the page ahead is blank, and the pen is in your hand, and the ink is your choices. But perhaps the truth braids them: the future is a book being written by the reading, each choice inscribing the very page it then encounters, so that it is both already-there and not-yet, authored in the instant it is lived. You are not reading your fate. You are its author and its first reader at once, writing the next line just fast enough to read it.
The Unread Page Is Still Blank to You.
Even suppose the cosmic verdict is in—the future fixed, determined, "written" in full. Notice it changes nothing you can feel, because the writing is in a language you cannot read until you have already lived it. To an all-seeing eye the story may be complete; to you, inside it, every page arrives blank and must be filled by choosing. Fate that cannot be known in advance is indistinguishable, from within, from freedom—and since within is the only place you will ever stand, the openness is, for all practical purposes, total. The book may be finished. You are still the one holding the pen, in the dark, writing what you cannot yet see.
The Door Quantum Physics Left Ajar.
For centuries the machine seemed sealed: present state plus iron law equals one inevitable future, the cosmos a clockwork grinding out its only possible next tick. Then the quantum world reported something wilder—that at bottom the present does not fix the future but only its odds, that genuine chance is woven into the weave. If so, the book is not merely unread but partly unwritten, its next words drawn, at the smallest scale, from a hat. Whether this randomness rises up to touch your choices is unknown. But the old certainty is gone: the universe may not know its own ending either.
The Fatalist's Comfortable Error.
There is a seductive whisper in "the future is written": then nothing I do matters, so I need not try. It is the oldest excuse there is, and it is a mistake so clean it can be pointed to. For even in a fully determined world, your effort is not bypassed—it is the very gear through which the determined future is produced. The lazy fatalist and the striving one do not share a fixed fate; they have different futures, precisely because they act differently, and the difference is their doing. To conclude from "it will be what it will be" that "so my choices are idle" is to forget that your choices are among the causes of what will be. The future may be written. But if it is, it is being written in your handwriting.
Whether the future is "written" splits into three questions usually confused: whether it is real, whether it is fixed by the present, and whether it is knowable. Physics may make it real, and perhaps fixed—though quantum chance may leave it genuinely open—but in every case it is unknowable in advance and shaped through your own choices. So even a fixed future is not a fated one: your deliberating is the mechanism by which it gets determined, which means fatalism—"nothing I do matters"—is an error, and from the only vantage you will ever occupy, the page ahead is blank and the pen is yours.