This is part of a weekly reading group on Nick Bostrom's book, Superintelligence. For more information about the group, and an index of posts so far see the announcement post. For the schedule of future topics, see MIRI's reading guide.
Welcome. This week we discuss the ninth section in the reading guide: The orthogonality of intelligence and goals. This corresponds to the first section in Chapter 7, 'The relation between intelligence and motivation'.
This post summarizes the section, and offers a few relevant notes, and ideas for further investigation. Some of my own thoughts and questions for discussion are in the comments.
There is no need to proceed in order through this post, or to look at everything. Feel free to jump straight to the discussion. Where applicable and I remember, page numbers indicate the rough part of the chapter that is most related (not necessarily that the chapter is being cited for the specific claim).
Reading: 'The relation between intelligence and motivation' (p105-8)
Summary
- The orthogonality thesis: intelligence and final goals are orthogonal: more or less any level of intelligence could in principle be combined with more or less any final goal (p107)
- Some qualifications to the orthogonality thesis: (p107)
- Simple agents may not be able to entertain some goals
- Agents with desires relating to their intelligence might alter their intelligence
- The motivations of highly intelligent agents may nonetheless be predicted (p108):
- Via knowing the goals the agent was designed to fulfil
- Via knowing the kinds of motivations held by the agent's 'ancestors'
- Via finding instrumental goals that an agent with almost any ultimate goals would desire (e.g. to stay alive, to control money)
Another view
John Danaher at Philosophical Disquisitions starts a series of posts on Superintelligence with a somewhat critical evaluation of the orthogonality thesis, in the process contributing a nice summary of nearby philosophical debates. Here is an excerpt, entitled 'is the orthogonality thesis plausible?':
At first glance, the orthogonality thesis seems pretty plausible. For example, the idea of a superintelligent machine whose final goal is to maximise the number of paperclips in the world (the so-called paperclip maximiser) seems to be logically consistent. We can imagine — can’t we? — a machine with that goal and with an exceptional ability to utilise the world’s resources in pursuit of that goal. Nevertheless, there is at least one major philosophical objection to it.
We can call it the motivating belief objection. It works something like this:
Motivating Belief Objection: There are certain kinds of true belief about the world that are necessarily motivating, i.e. as soon as an agent believes a particular fact about the world they will be motivated to act in a certain way (and not motivated to act in other ways). If we assume that the number of true beliefs goes up with intelligence, it would then follow that there are certain goals that a superintelligent being must have and certain others that it cannot have.
A particularly powerful version of the motivating belief objection would combine it with a form of moral realism. Moral realism is the view that there are moral facts “out there” in the world waiting to be discovered. A sufficiently intelligent being would presumably acquire more true beliefs about those moral facts. If those facts are among the kind that are motivationally salient — as several moral theorists are inclined to believe — then it would follow that a sufficiently intelligent being would act in a moral way. This could, in turn, undercut claims about a superintelligence posing an existential threat to human beings (though that depends, of course, on what the moral truth really is).
The motivating belief objection is itself vulnerable to many objections. For one thing, it goes against a classic philosophical theory of human motivation: the Humean theory. This comes from the philosopher David Hume, who argued that beliefs are motivationally inert. If the Humean theory is true, the motivating belief objection fails. Of course, the Humean theory may be false and so Bostrom wisely avoids it in his defence of the orthogonality thesis. Instead, he makes three points. First, he claims that orthogonality would still hold if final goals are overwhelming, i.e. if they trump the motivational effect of motivating beliefs. Second, he argues that intelligence (as he defines it) may not entail the acquisition of such motivational beliefs. This is an interesting point. Earlier, I assumed that the better an agent is at means-end reasoning, the more likely it is that its beliefs are going to be true. But maybe this isn’t necessarily the case. After all, what matters for Bostrom’s definition of intelligence is whether the agent is getting what it wants, and it’s possible that an agent doesn’t need true beliefs about the world in order to get what it wants. A useful analogy here might be with Plantinga’s evolutionary argument against naturalism. Evolution by natural selection is a means-end process par excellence: the “end” is survival of the genes, anything that facilitates this is the “means”. Plantinga argues that there is nothing about this process that entails the evolution of cognitive mechanisms that track true beliefs about the world. It could be that certain false beliefs increase the probability of survival. Something similar could be true in the case of a superintelligent machine. The third point Bostrom makes is that a superintelligent machine could be created with no functional analogues of what we call “beliefs” and “desires”. This would also undercut the motivating belief objection.
What do we make of these three responses? They are certainly intriguing. My feeling is that the staunch moral realist will reject the first one. He or she will argue that moral beliefs are most likely to be motivationally overwhelming, so any agent that acquired true moral beliefs would be motivated to act in accordance with them (regardless of their alleged “final goals”). The second response is more interesting. Plantinga’s evolutionary objection to naturalism is, of course, hotly contested. Many argue that there are good reasons to think that evolution would create truth-tracking cognitive architectures. Could something similar be argued in the case of superintelligent AIs? Perhaps. The case seems particularly strong given that humans would be guiding the initial development of AIs and would, presumably, ensure that they were inclined to acquire true beliefs about the world. But remember Bostrom’s point isn’t that superintelligent AIs would never acquire true beliefs. His point is merely that high levels of intelligence may not entail the acquisition of true beliefs in the domains we might like. This is a harder claim to defeat. As for the third response, I have nothing to say. I have a hard time imagining an AI with no functional analogues of a belief or desire (especially since what counts as a functional analogue of those things is pretty fuzzy), but I guess it is possible.
One other point I would make is that — although I may be inclined to believe a certain version of the moral motivating belief objection — I am also perfectly willing to accept that the truth value of that objection is uncertain. There are many decent philosophical objections to motivational internalism and moral realism. Given this uncertainty, and given the potential risks involved with the creation of superintelligent AIs, we should probably proceed for the time being “as if” the orthogonality thesis is true.
Notes
In-depth investigations
If you are particularly interested in these topics, and want to do further research, these are a few plausible directions, some inspired by Luke Muehlhauser's list, which contains many suggestions related to parts of Superintelligence. These projects could be attempted at various levels of depth.
- Are there interesting axes other than morality on which orthogonality may be false? That is, are there other ways the values of more or less intelligent agents might be constrained?
- Is moral realism true? (An old and probably not neglected one, but perhaps you have a promising angle)
- Investigate whether the orthogonality thesis holds for simple models of AI.
- To what extent can agents with values A be converted into agents with values B with appropriate institutions or arrangements?
- Sure, “any level of intelligence could in principle be combined with more or less any final goal,” but what kinds of general intelligences are plausible? Should we expect some correlation between level of intelligence and final goals in de novo AI? How true is this in humans, and in WBEs?
How to proceed
This has been a collection of notes on the chapter. The most important part of the reading group though is discussion, which is in the comments section. I pose some questions for you there, and I invite you to add your own. Please remember that this group contains a variety of levels of expertise: if a line of discussion seems too basic or too incomprehensible, look around for one that suits you better!
Next week, we will talk about instrumentally convergent goals. To prepare, read 'Instrumental convergence' from Chapter 7. The discussion will go live at 6pm Pacific time next Monday November 17. Sign up to be notified here.
There is more than one version of the orthogonality thesis. It is trivially false under some interpretations, and trivially true under others, which is true because only some versions can be used as a stage in an argument towards Yudkowskian UFAI.
It is admitted from the outset that some versions of the OT are not logically possible, those being the ones that involve a Godelian or Lobian contradiction.
It is also admitted that the standard OT does not deal with any dynamic or developmental aspects of agents. However, the UFAI argument is posited on agents which have stable goals, and the ability to self improve, so trajectories in mindspace are crucial.
Goal stability is not a given: it is not possessed by all mental architectures, and may not be possessed by any, since noone knows his to engineer it, and humans appear not to have it. It is plausible that an agent would desire to preserve its goals, but the desire to preserve goals does not imply the ability to preserve goals. Therefore, no goal stable system of any complexity exists on this planet, and goal inability cannot be assumed as a default or given.
Self improvement is likewise not a given, since the long and disappointing history of AGI research is largely a history of failure to achieve adequate self improvement. Algorithmspace is densely populated with non self improvers.
An orthogonality claim of a kind relevant to UFAI must be one that posits the stable and continued co-existence of an arbitrary set of values in a self improving AI. However, the version of the OT that is obviously true is one that maintains the momentary co-existence of arbitrary values and level of intelligence.
We have stated that goal stability and self impairment, separately, may well be rare in mindspace.Furthermore, it is not clear arbitrary values are compatible with long term self improvement as a combination: a learning, self improving AI will not be able to guarantee that a given self modification keeps its goals unchanged, since it doing so involves the the relatively dumber version at time T1 making an an accurate prediction about the more complex version at time T2. This has been formalised into a proof that less powerful formal systems cannot predict the abilities of more formal ones.
From Squarks article
http://lesswrong.com/lw/jw7/overcoming_the_loebian_obstacle_using_evidence/
"Suppose you're trying to build a self-modifying AGI called "Lucy". Lucy works by considering possible actions and looking for formal proofs that taking one of them will increase expected utility. In particular, it has self-modifying actions in its strategy space. A self-modifying action creates essentially a new agent: Lucy2. How can Lucy decide that becoming Lucy2 is a good idea? Well, a good step in this direction would be proving that Lucy2 would only take actions that are "good". I.e., we would like Lucy to reason as follows "Lucy2 uses the same formal system as I, so if she decides to take action a, it's because she has a proof p of the sentence s(a) that 'a increases expected utility'. Since such a proof exits, a does increase expected utility, which is good news!" Problem: Lucy is using L in there, applied to her own formal system! That cannot work! So, Lucy would have a hard time self-modifying in a way which doesn't make its formal system weaker. As another example where this poses a problem, suppose Lucy observes another agent called "Kurt". Lucy knows, by analyzing her sensory evidence, that Kurt proves theorems using the same formal system as Lucy. Suppose Lucy found out that Kurt proved theorem s, but she doesn't know how. We would like Lucy to be able to conclude s is, in fact, true (at least with the probability that her model of physical reality is correct). "
Squark thinks that goal stable self improvement can be rescued btpy probablist reasoning. I would rather explore the consequences of goal instability,
An AI that opts for goal stability over self improvement will probably not become smart enough to be dangerous.
An AI that opts for self improvement over goal stability might visit paperclippping, or any of a large number of other goals on its random walk. However, paperclippers aren't dangerous unless they are fairly stable paperclippers. An AI that paperclips for a short time is no threat: the low hanging fruit is to just buy them, or make them out of steel.
Would an AI evolve into goal stability? Something as arbitrary as papercliping is a very poor candidate for an attractor. The good candidates are quasi evolutionary goals that promote survival and reproduction. That's doesn't strongly imply friendliness, but inasmuch as it implies unfriendliness, it implies a kind we are familiar with, being outcompeted for resources by entities with a drive for survival, not the alien, Lovecraftian horror of the paperclippers scenario.
(To backtrack a little: I am not arguing that goal instability is particularly likely. I can't quantify the proportion of AIs that will opt for the conservative approach of not self modifying).
Goal stability is a prerequisite for MiRIs favoured method of achieving AI safety, but it is also a prerequisite for MiRIs favourite example of unsafe AI, the paperclipper, so it's loss does not appear to make AI more dangerous.
If goal stability is unavailable to AIs, or at least to the potentially dangerous ones -- we don't have worry to much about the non-improvers -- then the standard MIRI solution of solving friendliness, and coding it in as unupdateable goals, is unavailable. That is not entirely bad news, as the approach based on rigid goals is quite problematical. It entails having to get something exactly right first time, which is not a situation you want to be in if you can avoid it -- particularly when the stakes are so high.