Monday, June 30, 2014

SpaceTimeMind Podcasts: Alien and Machine Minds, Death and Logic

A couple of months ago, I had some great fun chatting with Richard Brown and Pete Mandik at SpaceTimeMind. Pete has now edited our conversation into two podcasts in their engaging, energetic style:

Part One: Death and Logic

Part Two: Alien and Machine Minds

The episodes are free-standing, so if the topic of Part Two interests you more, feel free to skip straight to it. There will be a few quick references back to our Part One discussion of modality and hypotheticals, but nothing essential.

Although I think Part Two is a very interesting conversation, I do have one regret about it: It took me so long to gather Richard's view about alien consciousness that I didn't manage to articulate very well my reasons for disagreeing. Something early in the conversation led me to think that Richard was allowing that probably there are (somewhere in the wide, wide universe) aliens constructed very differently from us, without brains, who have highly sophisticated behavior -- behavior as sophisticated as our own -- and that his view is that such beings have no conscious experience. By the end of the episode, it became clear to me that his view, instead, is that there probably aren't such beings (but if there were, we would have good reason to regard them as conscious). He offered empirical evidence for this conclusion: that all beings on Earth that are capable of highly sophisticated behavior have brains like ours.

If I had understood his view earlier in the conversation, I might have offered him something like this reply:

(1.) Another possible explanation for the fact that all (or most?) highly intelligent Earthlings have brains structured like ours is that we share ancestry. It remains open that in a very different evolutionary context, drawing upon different phylogenetic resources, a very different set of structures might be able to ground highly intelligent (e.g. sophisticated linguistic, technology-building) behavior.

(2.) Empirical evidence on Earth suggests that at least moderately complicated systems can be designed with very different material structures (e.g., gas vs. battery cars, magnetic tape drives vs. laser drives; insect locomotion vs. human locomotion). I see no reason not to extrapolate such potential diversity to more complex cognitive systems.

(3.) If the universe is vast enough -- maybe even infinite, as many cosmologists now think -- then even extremely low probability events and systems will be actualized somewhere.

Anyhow, Richard and Pete's podcasts have a great energy and humor, and they dive fearlessly into big-picture issues in philosophy of mind. I highly recommend their podcasts.

(For Splintered Mind readers more interested in moral psychology, I recommend the similarly fun and fearless Very Bad Wizards podcast with David Pizarro and (former Splintered Mind guest blogger) Tamler Sommers.)


  1. Seems to me that we will in a fairly short period of time (in the big scheme of things) modify our bodies to be largely based on something else (like silicone or something else that works well) and that over the life of the universe most intelligent aliens would be likely to exist in a form that was in this more optimal design rather than the one they happen to evolve.


  2. GNZ: Nice angle on the issue. I'm guessing Richard thinks that won't work for brain functioning -- that there will be something very special that will need to be preserved and cannot be implemented non-biologically or in multiple radically different ways.

  3. Re: "will need to be preserved". There are at least two issues smooshed together here. One is what needs to be preserved in order to count as conscious or intelligent. The second is what needs to be preserved in order to maximize evolutionary fitness. My bet, and I got into this a bit toward the end of episode 8, is that creatures who take a metaphysically daring stance toward the first question (e.g., by choosing to view their upload counterparts as their continuants) will be more evolutionary successful than their metaphysically timid competitors, regardless of what the *right* answer is (or whether there even is one) to the first question.

  4. Yes, that's an interesting thought, Pete. And if it's true, it probably does create some pressure on the first issue as well, in the sense that even if the daring is highly improbable in the universe, once actualized such entities will probably proliferate, creating a certain kind of moral and pragmatic pressure to include them.