Bayesian Ethics

As I’ve written before, one of my past wrestles is with Utilitarianism: that the moral act is the one with the best consequences regardless of what rules it breaks. I’m now firmly Aristotelian – aka a ‘virtue ethicist’ – we are what we repeatedly do.

But Anthony Appiah the Princeton Philosopher has some challenging things to say about virtue ethics in a Philosophy Bites podcast – including some experiments. And I’m inclined to listen. I like a bit of scientific method.

I like Appiah’s ‘Cosmopolitanism’ too which has helped me articulate my ‘live and let live’ theory of internationalism at work. Humans value culture. Different cultures value different things. And Cosmopolitanism says, short of harm, we should let them. Which I think is about right.

Appiah challenges virtue with ‘experimental ethics’ – seeing what people actually do, rather than what we theorise, and looking inside people’s heads in brain scanners. He finds, for example, nearly everyone gets more generous to strangers if they find a suitably planted $10 note on the floor.

His conclusion is that the idea of a ‘moral’ person in the Aristotelian sense is not borne out by the experimental reality. For him, we make moral choices based on context, stimulus and ‘in the moment’ not based on ‘character’. I don’t entirely agree, but it’s interesting stuff.

Learning to use the head to override the instinctive ‘yuk’ response or being over-influenced by the situation is one of the things he advocates. But only sparingly. Here’s where rules, norms and culture – plus a moral education – might help. But he’s not for becoming too calculating.

He disagrees with Utilitarianism for example. First, because it doesn’t capture the experimental reality of how we respond to moral situations. Second, because were to implement calculating ‘consequentialism’ wide-scale it would dramatically impoverish human existence. Largely because promoting purely rational calculation would tend to demote difference and different views.

Cultural Cosmopolitanism makes life interesting and liveable. And if you’re going to accept difference in culture you have to accept it in worldview and ethics too. That people care about different things is what makes people interesting – and maddening.

I personally think virtue and ‘outlying’ single instances of behaviour are not incompatible. I don’t doubt that you can get very good and very bad moral choices and behaviours out of me if you significantly change my conditions and stimuli.

I also think that the prospects of me making better or worse choices are determined, yes, by the context and circumstances – but crucially, combined with who I am. And who I am is the product of a life lived, previous choices made, data, concepts and theories within and Bayesian probability mashing all that together in a nano-second every time I act.

I think there is ‘virtue’ and I have a ‘character’. It’s just that the complexity of the probabilistic calculations – all done subconsciously by that marvel of existence, a human brain – mean Utilitarianism is too crude and individual ethical experiments are too simple to anything like capture them. I return to my own dictum – if the human brain were simple enough to understand, we’d be too simple to understand it.

So I like Appiah’s ethical experiments – they deserve a well signposted place in my Bayesian brain’s data set – and I’ve shared then with others too to influence them. But virtue, character and Aristotle’s ‘I am what I repeatedly do’ still work best for me. Thanks to Appiah though, I’m also a Cosmopolitan. So I’m delighted to weigh a well-wrought difference of opinion in the Bayesian ethical balance. It all goes in the mix.


This week, I advanced my new theory – to a gently sceptical friend – that the brain works (at least partly) like the electronic ink screen of an Amazon Kindle. Blending in the philosophy of St Thomas Aquinas, my sweeping conclusion was he should get angry more. Here’s why.

Since buying a Kindle, I’ve been impressed that the screen, when you switch it off, maintains a complex picture – a person, a constellation, a painting etc – using no energy at all. It’s simple but impressive. Like a screensaver, but without power. Information and knowledge are thus available to be viewed, at any time, at no energy or processing cost. My theory is the brain has the same capacity.

A few years ago I read that neurones aren’t permanently ‘charged’ like little lightbulbs or LCD pixels but store information passively – more like a physical switch or dial. Energy is used to ‘charge’ them with information, but once they have been ‘set’ with information they store it passively until changed. Good job too, or, given the number of neurones we have, we’d need a nuclear generator to power our heads.

So my emerging thesis is we can ‘poll’ in computer lingo, or rapidly access a snapshot our entire accumulated summary of knowledge and experience in an instant. And in that instant we can act or react subconsciously informed by that summary.

My guess is that none of this requires much in the way of conscious cognitive processes. Like a finger recoiling from a nail or a smile drawing a return smile, we can immediately and effectively respond to people and situations against this dataset. I’m not saying it is innate or preloaded. We are constantly checking, updating and rearranging our vast neuronal data-set. But at any instant, my thesis is, it lies latently ‘there’ encrypted in neurones like the patterns which make a rich picture, or a page of words, out of electronic ink.

Of course we can intervene, ignore, debate or challenge our accumulated data. Any instant ‘gut’ reaction, or action, it may recommend can be overruled. In complex or nuanced circumstances the higher cognitive functions kick in – at least most of the time.

And this connects to my ongoing conversation with my friend on Aquinas’ support for ‘ira’, and the set of passions which include anger. Like Aristotle – in fact far more than him – Aquinas was pro anger in the right circumstances. Surprising for a theologian.

He thought the passions were intrinsic parts of who we are. He thought they were forms of reason, not lower ‘animal’ or ‘bodily’ sensations to be suppressed by our purer ‘mind’ or ‘soul’. Thus, our passions come from our instincts, blended with our default ‘Kindle screen’ summary of experiences, beliefs and our lifetime of accumulated and refined knowledge. They all inform each other.

I’m with Aristotle that we are what we repeatedly do. So we are constantly refining and tuning our passions, our experience dataset and our virtues through action – only some of that helped by conscious reflection. I’m increasingly with Aquinas too, that it all comes together in complex single holistic system – an ‘anima’, aka a person, not a dumb body and a smart, reasonable mind.

As Herbert McCabe points out: for Aquinas the good life is a passionate life; not achieved by the repression of passions, but by passions guided by virtues. Perhaps there’s more to be said for trusting our ‘gut’, allowing moments of ‘ira’ and the occasional incandescence of righteous anger. Once you’ve lived a few decades and developed a bit of virtue, it’s pretty well informed.