A defense of formal philosophy

post by lukeprog · 2012-02-17T14:45:17.024Z · LW · GW · Legacy · 8 comments

Gregory Wheeler has written an eloquent new defense of formal philosophy.


...formal epistemology is an interdisciplinary research program that includes work by philosophers, mathematicians, computer scientists, statisticians, psychologists, operations researchers, and economists which aims to give mathematical and sometimes computational representations of, along with sound strategies for reasoning about, knowledge, belief, judgment and decision making.


Why... bother being so formal? [Rich] Thomason, commenting on philosophers who view formal methods as a distraction to real philosophical advancement, observed that the only real advantage that we have over the great philosophers of the past are the new methods that we have at our disposal. Probability. First-order logic. Calculus. The number zero. It is hard to imagine improving on Aristotle without resorting to methods that were simply unavailable to him. Knowing just this much about history, a better question is this: why limit your options?


The problem with aspiring to counterexample-proof philosophy without taking into account either formal or empirical constraints is that the exercise can quickly devolve into a battle of wits rather than a battle of ideas. And the problem is only compounded by pseudo-formal philosophy — the unfortunate practice of using formal logic informally — because this encourages philosophers to describe rather than define the fundamental operations of their theories. Memories are ‘accessed in the right way’; justified beliefs are ‘based’ on one’s ‘evidence’; coherent beliefs ‘hang together’. But, like a bump in a rug carefully pushed from one corner of a crowded room to another, this reliance on pseudo-formalisms to avoid any and all counterexamples inevitably means that the hard, unsolved philosophical problems are artfully avoided rather than addressed. At its worst, rampant counterexample avoidance turns philosophy into little more than a performance art.

But, one way to arrest this slide is by constraining epistemological theories by a combination of empirical evidence and formal models. For if you replace those fudged terms with a formal model, or a provably correct algorithm, and hem in imagination by known empirical constraints, then if a theory is successful in explaining a range of cases, that hard won success can be weighed against the theory’s failings. In other words, if we set aspirations for epistemology higher than conceptual analysis, that will open more room to judge success and failure than the all-or-nothing stakes of counterexample avoidance.

See also: An Overview of Formal Epistemology.


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comment by Manfred · 2012-02-18T04:05:03.673Z · LW(p) · GW(p)

It is hard to imagine improving on Aristotle without resorting to methods that were simply unavailable to him.

Just wanted to remind everyone that this is straight-up false. Aristotle assumed a lot of wrong things to prove also-wrong things. For example, Aristotle proved lots of stuff based on the infallibility of sensation, but since that's a false premise, all that stuff was pointless. It's not at all impossible to surpass historical figures, because not just believing what you like is fairly rare and gets rarer the further back in scientific progress you go.

Replies from: antigonus, Jayson_Virissimo, TheAncientGeek
comment by antigonus · 2012-02-18T04:32:53.629Z · LW(p) · GW(p)

For example, Aristotle proved lots of stuff based on the infallibility of sensation

I don't know much about Aristotle, but this claim sounds to me like a distortion of something Aristotle might have said.

Replies from: Manfred
comment by Manfred · 2012-02-18T10:39:09.316Z · LW(p) · GW(p)

Hm, well, after a little looking into it I think my criticism wasn't the best characterization ever, but not entirely unfounded.

The bad stuff is like this: http://classics.mit.edu/Aristotle/soul.html

The reason my criticism was bad is because it was unspecific - a mostly undeserved general impugning rather than noting a specific problem. Which is mostly because I don't enough to point at a specific problem.

Replies from: Tyrrell_McAllister, Jayson_Virissimo
comment by Tyrrell_McAllister · 2012-02-19T19:06:47.168Z · LW(p) · GW(p)

The bad stuff is like this: http://classics.mit.edu/Aristotle/soul.html

What exactly seems so bad about On The Soul? As I recall, it was about as reasonable a theory as anyone could have at the time. If I recall correctly, it basically identified the soul (i.e., whatever makes organisms capable of moving themselves) with how the physical parts of the body are organized. This certainly compares favorably to other pre-scientific theories, such that the soul is a nonphysical spiritual entity (as Christians believe), or a cloud of special soul particles (as the Greek atomists taught), or some mysterious élan vital (as many pre-20th century biologists held).

Replies from: Manfred
comment by Manfred · 2012-02-20T00:26:27.406Z · LW(p) · GW(p)

Well, I'd agree that it's much better than élan vital. And as I'm reading it because of this discussion, it really isn't about the modern conception of souls - "de anima" here is more like "on the essence of animals." But there are plenty of individual wrong conclusions, where one could "improve on Aristotle without resorting to methods that were simply unavailable to him." Skimming through book 3, we get stuff like this:

That there is no sixth sense in addition to the five enumerated-sight, hearing, smell, taste, touch-may be established by the following considerations:


Therefore, since everything is a possible object of thought, mind in order, as Anaxagoras says, to dominate, that is, to know, must be pure from all admixture; for the co-presence of what is alien to its nature is a hindrance and a block: it follows that it too, like the sensitive part, can have no nature of its own, other than that of having a certain capacity. Thus that in the soul which is called mind (by mind I mean that whereby the soul thinks and judges) is, before it thinks, not actually any real thing. For this reason it cannot reasonably be regarded as blended with the body: if so, it would acquire some quality, e.g. warmth or cold, or even have an organ like the sensitive faculty: as it is, it has none.


the soul is in a way all existing things; for existing things are either sensible or thinkable, and knowledge is in a way what is knowable, and sensation is in a way what is sensible

("in a way" here meaning that like is required to sense like, and like is required to recognize like thoughts. So, false)


An animal is a body with soul in it: every body is tangible, i.e. perceptible by touch; hence necessarily, if an animal is to survive, its body must have tactual sensation.


Okay, I think that's enough. So I do now feel that De Anima is better than I'd represented it as, but it invents models more complicated than justified, and so gets some wrong conclusions, which could have been avoided if stuff had not been made up.

comment by Jayson_Virissimo · 2012-02-19T09:37:04.748Z · LW(p) · GW(p)

The bad stuff is like this: http://classics.mit.edu/Aristotle/soul.html

So, what is particularly bad about the arguments in Aristotle's On the Soul?

comment by Jayson_Virissimo · 2012-02-19T09:34:11.315Z · LW(p) · GW(p)

For example, Aristotle proved lots of stuff based on the infallibility of sensation, but since that's a false premise, all that stuff was pointless.

Could you direct me to where Aristotle asserts that data from the senses are infallible? If I remember correctly, Aristotle defended a kind of virtue epistemology where sense data could only be trusted under very strict conditions and by someone virtuous enough (in rationality) to interpret the experiences correctly.

comment by TheAncientGeek · 2014-11-02T09:08:40.852Z · LW(p) · GW(p)

The infallibility of the senses sounds more like Rand.