i haven’t seen an ask from you, so apparently the latter, if i understand correctly?Ha ha I love this website. Trying again.
Augh ok @nostalgebraist I was just asking if you’d read the functional decision theory paper from Yudkowsky and Soares, trying to decide if it’s worth reading and wondering if you had thoughts
I haven’t looked at it yet.
Do I understand correctly that FDT is the latest “TDT but it works this time” iteration? If so, that’s neat if and only if it actually works this time, which has been frustratingly difficult to ascertain from the discussion I’ve seen so far (which all looks to me like people arguing over whether TDT is a good idea in the first place).
It doesn’t seem like this paper contains any technical improvements to TDT itself. Section 3 says
If a certain decision function outputs cooperate on a certain input, then it does so of logical necessity; there is no possible world in which it outputs defect on that input, any more than there are possible worlds where 6288 + 1048 6= 7336. The above notion of subjunctive dependence therefore requires FDT agents to evaluate counterpossibilities, in the sense of Cohen (1990), where the antecedents run counterto-logic. At first glance this may seem undesirable, given the lack of a satisfactory account of counterpossible reasoning. This lack is the main drawback of FDT relative to CDT at this time; we will discuss it further in section 5. […]
Instead of despairing at the dependence of FDT on counterpossible reasoning, we note that the difficulty here is technical rather than philosophical. Human mathematicians are able to reason quite comfortably in the face of uncertainty about logical claims such as “the twin prime conjecture is false,” despite the fact that either this sentence or its negation is likely a contradiction, demonstrating that the task is not impossible. Furthermore, FDT agents do not need to evaluate counterpossibilities in full generality; they only need to reason about questions like “How would this predictor’s prediction of my action change if the FDT algorithm had a different output?” This task may be easier. Even if not, we again observe that human reasoners handle this problem fairly well: humans have some ability to notice when they are being predicted, and to think about the implications of their actions on other people’s predictions. While we do not yet have a satisfying account of how to perform counterpossible reasoning in practice, the human brain shows that reasonable heuristics exist.
which I guess can be paraphrased as “no, it doesn’t work yet”. Their formalization assumes that the agents are provided with a graph G which encodes “the logical, mathematical, computational, causal, etc. structure of the world more broadly”—I think this is exactly what Yudkowsky’s long TDT draft paper did also. (So I’m not sure why they renamed it from TDT to FDT?)
Rather, the point of the paper is to give philosophical arguments for why this decision theory is preferable to CDT and EDT. The arguments are basically similar to what was posted on Overcoming Bias a decade ago, but worked out much more thoroughly.
The writing is really good now! The prose is succinct, the examples are both enlightening and clearly described, and it makes a point of comparing to related work from the academic philosophical literature. I feel it’s very convincing, but then again I was convinced already. I wonder what ogingat would say.
… huh. If this is true, I guess I’m confused why this paper exists. Are they just trying to get the attention of philosophy academia again, like the time they tried to hire a philosophy prof to write up TDT?



