倒寄的信：论后悔，是把B点的认识寄回A点

**我们后悔时，是对当前的状态不满，我们觉得当初就能看到当前这个状态。** **这不需要造一条从未发生的支路。被抱怨的那个状态，就是实际发生、此刻已知的那一个——A点。** **而后悔要求的，只是一件事：那份此刻（B点）才有的认识，倒着传回A点。** **"我早该想到会是这样。"** 这句话的意思是：**站在A点的我，本该已经拥有此刻站在B点才拥有的这份认识。** **而A点那一刻，B点还没发生。任何要传给A的东西，都还不存在。** **没有东西可传，就没有东西可倒寄。** **——所以不是"我没收到那封信"，是那封信在A点还没有被写出来。** **这跟"人只是视线不能拐弯"是同一条限制，只是错认的位置不同，而且方向相反。** **在走的那一刻（A点），错认是：** 因为看不见后面的形状，就以为自己"把直的弄弯了"（一份把不存在的原型误认为存在的错觉）。 **而在回头看的这一刻（B点），错认是：** 因为已经站在了拐弯之后，看见了整段形状，**就以为那份"看见"原本在A点就该有**（一份把此刻的认识误认为当时就有的错觉）。 **一个在线的前端犯错，一个在后端犯错——而两个错认，用的是同一条被压扁的四维线。** **一个可以自己验的检验：找一次你说过"我早该想到"的时候，问自己——那句话，是在事情发生之前说的，还是之后？** **从来都是之后。** **没有人在A点说"我现在已经看到B点会是这样"。** 那句话，只在站到B点之后才会被说出来——**而正是这个"只在之后"，暴露了这份认识的真正产地：它是B点自己的，不是A点的。** ## Abstract **When we regret something, we are dissatisfied with the present state, and feel that we could have seen this present state coming.** **This requires no imagined branch that never occurred. The state being complained of is exactly the one that actually happened and is now known—point A.** **And regret asks for only one thing: that the knowledge available now, at point B, be mailed back to point A.** **"I should have known it would come to this."** The sentence means: **the self at A ought already to have possessed the knowledge that the self at B now possesses.** **But at the moment of A, B had not yet occurred. Nothing that could be sent to A existed yet.** **With nothing to send, there is nothing to mail back.** **—So it is not "I never received that letter"; it is that the letter had not yet been written at A.** **This is the same limit as "the line of sight simply cannot bend," only the site of the error differs, and runs the other way.** **At the moment of walking (point A), the error was:** unable to see the shape ahead, one takes oneself to have "bent something straight" (an illusion mistaking a nonexistent original for an existing one). **At the moment of looking back (point B), the error is:** having already stood past the bend and seen the whole shape, **one takes that "seeing" to have been owed already at A** (an illusion mistaking present knowledge for knowledge held at the time). **One error at the front end of the line, one at the back—and both use the same flattened four-dimensional line.** **A test anyone can run: recall a time you said "I should have known," and ask—was that said before the event, or after?** **Always after.** **No one at A says "I can already see how B will turn out."** That sentence is said only once one is standing at B—**and this "only afterwards" exposes the true provenance of the knowledge: it belongs to B, not to A.**