‘A woman of wisdom,’ Brennan said, ‘once told me that it is wisest to regard our past selves as fools beyond redemption – to see the people we once were as idiots entire. I do not necessarily say this myself; but it is what she said to me, and there is more than a grain of truth in it. As long as we are making excuses for the past, trying to make it look better, respecting it, we cannot make a clean break.’

– http://www.overcomingbias.com/2008/05/eld-science.html

I stumbled across the above quotation the other day when chasing links from another blog, and it inspired me to get round to writing up something I've been thinking about for a while.

I can understand and agree with Brennan's observation that there is some truth in the quoted proposition; but where he says he doesn't ‘necessarily’ agree with it completely, I'd go further than that and say that I strongly disagree with it as a universal premise. One of the things I'm most pleased with about my own mind is my ability to trust my past self, when it's appropriate.

This typically occurs when you've previously given some thought to a situation, and decided – dispassionately, carefully, and in a calm and collected fashion – what would be the best thing to do in that situation. But suppose the nature of the situation is … I want to say ‘emotionally loud’, by which I mean that it evokes some sort of strong concentration-disrupting emotions, possibly conflicting ones, when you're in it for real. Now your emotions are screaming at you to do something other than what you previously thought you should do, or perhaps even several contradictory other things. Worse still, they corrupt and seduce your rational thought processes, so that the wrong courses of action are not merely emotionally desirable, but now even seem sensible to you because your brain has got into a state where it's wilfully forgotten all the reasons why they're not.

At this sort of moment, the only thing arguing in favour of your pre-prepared choice is the memory that it's what you decided when you were thinking straight. To let that small quiet voice of memory, shorn of all its supporting reasoning and arguments, overrule all the reasons why the other courses of action seem obviously right to you right now takes a certain measure of stubbornness, a certain measure of self-control, but even more than both it takes something that I tend to think of as self-trust to motivate you in the first place to exercise that self-control and stubbornness: one is trusting one's past self to know better than one's current self, and consciously abdicating the attempt to decide on a course of action in favour of letting it decide for you.

It's even more difficult if you haven't considered the exact situation before, but have merely thought about things distantly related to it and worked out some general and extremely vague principles of wisdom (of the general level of vagueness of, say, ‘don't overreach’). To act on one of those principles when your emotions have seduced your rational thought processes into being convinced that the details of the current situation render the principle inapplicable requires considerable self-trust.

I don't claim to be outstanding at displaying this quality. But I manage it on a reasonably regular basis, and it's one of the things that makes me feel most pleased with myself afterwards: when my head is once again clear I'm able to look back on what I did in the middle of the chaos, remember all the reasons why it really was the right thing to do, and take pride in having managed to do it in spite of having forgotten all those reasons at the time I made the choice.

Science fiction occasionally writes about super-rational beings – whether AIs, aliens, superevolved humans or merely highly trained actual humans – which are capable of making the right decision for the right reasons by means of having their reasoning processes actually be unaffected by emotional pressure (except in that they can note the existence of those emotions and dispassionately treat them as another datum to reason with). In the absence of that highly desirable but frankly unrealistic capability, I tend to think that self-trust of this nature is the closest we poor mortals can come to achieving the same effects. The sage Brennan quotes above would have us throw out, with the bathwater of closed-minded unwillingness to revise an entrenched but wrong opinion, that not inconsiderable baby.