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Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: Decisions: Ontologically Shifting to Determinism, published by Chris Leong on December 21, 2022 on The AI Alignment Forum.In a previous post, I posited that a significant portion of the confusion surrounding counterfactuals can be traced back to an ontological shift. In this post, I will seek to elaborate on this argument and explain how we should reinterpret decision theory problems in light of this insight.Our Naive Ontology Assumes Libertarian Free WillConsider our naive ontology, by which I mean how humans tend to think without substantial philosophical reflection. In our naive ontology, we assume both that:That we possess libertarian free will, ie. that our choices are not predetermined before we make them.That when we're making a decision, both the past and present state of the universe are fixed independent of that decision.Unfortunately, scientific evidence seems to indicate:3. At the point of a decision, each brain-state only corresponds to one possible choiceIt is impossible for all of these statements to be true simultaneously. If they were, there would be multiple possible choices we could make, each of which would necessitate a different brain-state. However, this would also require the current state of the universe, and therefore our brain state, to be fixed independent of these choices.From my perspective, it is clear that the mistake was in assuming the existence of libertarian free will (assumption 1). Given this, I'll take it for granted that we have to revise our naive conception of decisions so as to be rooted in a deterministic ontology.Adapting to Determinism by Augmenting with CounterfactualsDeterminism dictates that whatever decision is ultimately made was the only decision that could have ever been made. This immediately poses a challenge: how do we avoid any decision from ending up as a trivial one?The obvious answer is that we must find a way to augment the factual with a counterfactual for each option we desire beyond the first. But how should we construct this and what kind of object should it even be?In Favour of Consistent CounterfactualsAs I previously argued in my post Counterfactuals are an Answer, Not a Question, the definition of a counterfactual will depend on the types of questions we seek to use them to answer. For example, while Causal Decision Theory results in counterfactual scenarios that are inconsistent, they can still be useful in practice, because the inconsistencies are often not relevant to the decisions we are attempting to make.To illustrate, we typically disregard the fact that making a decision would result in a different brain state, which would then lead to numerous changes in the past. However, when considering Newcomb-like problems within a deterministic framework, these are exactly the types of facts about the world that we cannot ignore. While it may not be immediately obvious that we should handle Newcomb-like problems by backpropagating the full effects of our decision backwards in time, it is clear that we must backpropagate at least some of these consequences. It is possible that someone may devise a concept of counterfactuals that allows for the selective backpropagation of certain consequences. However, at present, I can't see any obvious ways of accomplishing this, leading me to favour full propagation at least until a better theory arises.Furthermore, once we have begun backpropagating even some consequences, there is a compelling argument to be made for fully embracing this approach as we have already relinquished the primary benefit of not backpropagating consequences. This benefit is that since the past was fixed between counterfactuals, it is easier to justify that the counterfactuals were a fair comparison of the different choices.However, once we've accepted the need for some de...