# Newcomb's Paradox **URL:** \ **Category:** Logic & Philosophy of Mathematics\ **Created:** [March 11, 2026, 3:09am UTC](https://www.thephilosophyforum.com/t/newcombs-paradox/298 "2026-03-11T03:09:32Z")\ **Posts on this page:** 1\ **Showing post:** 493
**Author:** ![AlveK](https://yyz1.discourse-cdn.com/flex007/user_avatar/www.thephilosophyforum.com/alvek/32/594_2.png) [@AlveK](https://www.thephilosophyforum.com/u/AlveK)\ **Post date:** [March 16, 2026, 2:13am UTC](https://www.thephilosophyforum.com/t/newcombs-paradox/298/493 "2026-03-16T02:13:32Z")
(all bold in this post by me) > [@Pierre-Normand](#): > > What my diagram shows is that the predictor’s anticipation and the agent’s choice both flow from a **common source** : (…) No shit. This is called _correlation due to common cause._ It is one of the forms of _non-causative correlation._ **If there is an element that I cannot cause, then it is irrelevant to my decision-making; for my decision-making seeks to cause something.** > [@Pierre-Normand](#): > > The answer is: it doesn’t. There is **no determination** running from the choice to the anticipation: not ontic, not epistemic, **not any third kind**. You are looking for an arrow that **my position says does not exist** , and treating its absence as a deficiency rather than as the point. So, the absolute lack of any consistency in your stance shows that you have nothing but a deepity. Your stance is a bar of soap: the second I grasp it, it flies out of my hand. I can prove that you are contradicting yourself here. With the below quotes, we see that you have been maintaining that the player’s Phase 2 choice **determines** the contents of Box 2, in _some way._ Here: > [@Pierre-Normand](#): > > (…) it is precisely what _makes_ the agent’s Phase 2 deliberation **causally efficacious** with respect to the content of the opaque box. > [@Pierre-Normand](#): > > What there _is_ is a kind of **causation** — **rational** **causation** — that the CDT framework doesn’t recognize. > [@Pierre-Normand](#): > > It is a **practical determination** (…) > [@Pierre-Normand](#): > > The predictor has made the agent’s practical knowledge **causally efficacious** with respect to the very facts the agent is deliberating about. > [@Pierre-Normand](#): > > So **the determination** is neither merely epistemic (“sad news”) nor “ontically retrocausal.” It is **the distinctive determination** that practical knowledge has with respect to what it understands. > [@Pierre-Normand](#): > > You wonder what **semantic space** there might be between ontic and epistemic **determination**. > > (…) > > Within that framework, there genuinely is no **third option** , and I grant that my position must sound a bit like a blur of the two. > [@Pierre-Normand](#): > > You asked: “What changes, then?” I think the question is revealing precisely because it presupposes that **determination** must involve one thing changing another thing. > [@Pierre-Normand](#): > > **Practical determination** , though, is not a matter of _changing_ but of _making it the case_. > [@Pierre-Normand](#): > > My view is not that the agent’s choice stands in **some novel binary relation** to the box contents. > [@Pierre-Normand](#): > > As for **P-determines** : I haven’t given it up. Of course, this _determination_ that you are so determined to not define, it relates to your flirtation with retro-causation: > [@Pierre-Normand](#): > > On the view I’m defending, the diagram needs to be redrawn, not by adding a new arrow, but by collapsing two nodes. > [@Pierre-Normand](#): > > But your Phase 1/Phase 2 distinction draws the cut between past and present at the moment of deliberation and assigns the predictor’s action entirely to the “fixed past” side. > [@Pierre-Normand](#): > > It [CDT] holds the predictor’s action fixed because it treats it as part of “the past,” **causally insulated** from the agent’s **present** reasoning. So, you _fault_ CDT for holding the predictor’s action **causally insulated** from the player’s **present reasoning?** The predictor does **not cause** the player to make their choice in Phase 2. And the player’s choice in Phase 2 does **not cause** the predictor to fill Box 2 accordingly. The former violates the entire premise of the Newcomb Game, and the latter would be retro-causation. Lastly, there is this point of yours I missed: > [@Pierre-Normand](#): > > And the 1% failure rate comes from the predictor’s imperfect sensitivity to those grounds, as your own diagram already shows. Firstly, you have misinterpreted my diagram. For simplicity, I said the predictor had **perfect sensitivity** to the player’s predisposition, but that the player’s predisposition only ontically determined the player’s choice in Phase 2 with 99% likelihood. Flipping this picture is not an alternative. Doing so would imply people’s rational profile never changes, and that people never violate their own rational profile. The only way to disagree with my diagram on that front, then, would be to say that the predictor’s sensitivity is _also_ imperfect, but all that does is add some extra uncertainty to its prediction. It changes nothing fundamental about the scenario. ## Conclusion You do not have a consistent view, Pierre. I hope your fellow OBs, @Michael, @noAxioms, @Sime, @Patterner, @FlannelJesus can see this. All of you, _look at the quotes!_ **There either is a determination between the player’s choice and Box 2’s contents… or there isn’t.** If it’s **merely epistemic** , it is not sufficient, as Pierre has agreed. And if it is causal, then it is retro-causal, which Pierre has also agreed is not correct. Please, let us hold each other accountable. Pierre is claiming a different thing in every post. I have been claiming the exact same things the whole time, and my claims are clear and rigorous. You may disagree with my claims. **However, I expect none of you are confused about _what_ I believe.** Conversely, I think _even Pierre_ is confused about what Pierre believes. --- _[View the full topic](https://www.thephilosophyforum.com/t/newcombs-paradox/298)._