Friday, March 21, 2008

The Limits of Rationality

For the purposes of this blog post, I am defining rational thought as the process of deriving valid inferences from a set of premises.
As such it has a very limited domain within human affairs but makes a very important contribution for all that.
Sometimes people seem to argue that the supporters of secular liberal democracies should educate the children of religious adherents about the logical inconsistencies in religious beliefs in order to make the decline of religious fundamentalism more likely. Ironically though, this might ignore the evidence on what religious adherence entails and what benefits it might have.

Usually when humans attempt to compete directly with evolution in terms of creating artifacts that mimic the behaviour of biological mechanisms, evolution wins against our gadgets created by rational thought. Whilst we can make things that biology has not and perhaps could not, when we have tried to build things that walk across rough terrain unaided, or things that can recognise speech or images, our attempts so far have come a poor second. (Though we are doing a little better these days.)

When it comes to trying to solve some of the problems of life or engaging in creative activity that we consider worthwhile, it seems to me we must turn to non rational means. Some problems seem intractable when faced via reason. How to deal with loss and the knowledge of our own ultimate decline and demise perhaps. Other areas seem to positively benefit from the suspension of reason:
'Of course, you could be uncompromisingly rational and try whispering in your honey's ear: "Darling, you're the best combination of secondary sexual characteristics and mental processing that my fitness calculator has come up with so far." After you perform this pilot experiment and see how far you get, you may reconsider your approach. If you think that approach absurd to begin with, it is probably because you sincerely feel, and believe in, love.' Scott Atran

Perhaps evolution and culture have equipped us with ways of thinking that are non rational in terms of the strict definition I have used here, but that solve some practical problems better than rational thought does. Here is another example from Atran taken from his reply to Sam Harris after the first Beyond Belief conference:

"A research team that I co-directed in the Maya Lowlands for more than a decade — including psychologists, biologists, linguists, and anthropologists — found that only one of three human populations that live in the same environment practices agro-forestry in a sustainable manner (measured in terms of crop diversity, canopy cover, soil nutrients, etc., as reported in Proceedings of the National Academy of Sciences USA). We found the most reliable predictor of behavioral differences between the three groups (Itza' Maya, Q'eqchi' Maya, Ladino) to be their respective mental models of how humans, plants and animals interact in the rainforest (reported in Current Anthropology and The Journal of the Royal Anthropological Institute). And the best indication of a sustainable distribution of species for the forest was the mental model held by the men of one group (computed by factor analysis from individual responses) of which species the forest spirits desire most to protect (this is reliably different from what people themselves consider most worthy of protection, as reported in Psychological Review). " Scott Atran

Read the rest here.