Popper's Milestone

What do we mean when we talk about ‘metaphysics’? It seems inevitable that the answer to this question will be tediously complex, and yet we do possess a surprisingly neat and simple solution thanks to the work of the Austrian-born British philosopher Sir Karl Popper. In his efforts to explore the question ‘what is science?’ Popper inadvertently laid down a metaphorical stone marker which stands on the borders between science and metaphysics, providing us the option to distinguish simply between the two.

All explanations of metaphysics tend to stray into historical sidelines; perhaps the simplest explanation of metaphysics is to claim (unfairly!) that all the abstract nonsense philosophers discuss with no direct relevance to every day life such as Universals, Necessity and Possibility, notions such as Final Causes and so forth – all this is the realm of metaphysics. One can understand quite easily why someone might have cause to oppose metaphysics as meaningless, or at least unhelpful, given this admittedly misleading definition. 

The most infamous challenge of this kind came from a movement known as Logical Positivism which grew out of the infamous Vienna Circle of the 1920’s, which Wittgenstein was at first associated with, and later went to great lengths to oppose. Enamoured with the successes of science in the previous century, the Logical Positivists proposed that propositions gain their meaning by some specification of the actual steps taken to determine their truth or falsehood (the so-called verification principle). This focus on truth values is a common property in sceptical thought. Critically, it was the view of the Logical Positivists that metaphysics was meaningless since everything within this domain was unverifiable. 

Popper thought differently. To his mind, the success of science did not lie in it being more verifiable than metaphysics (or, for that matter, than ethics). Unlike many scientists, Popper took a decidedly cool view on induction (following Hume’s approach to the matter) and observed that it wasn’t possible to confirm a universal scientific theory as this would require absolutely complete knowledge, but that it was possible to disprove a universal theory.

The relevant flaw in induction can be shown by a simple thought experiment. Suppose we have an infinitely large sock drawer (or one with so many socks within it that it is effectively infinite). Every day, we pull two socks from this drawer, and every day both are black. We might conclude via the process of induction that the sock drawer contains only black socks. But suppose one day we reach in and pull out a white sock. This immediately invalidates the ‘black sock theory’! In the same way, a scientific theory cannot be proved to be true, but it can be falsified by contradictory evidence.

Popper advanced the idea that falsification was a more useful criteria to apply to science than the verification principle, since universal theories can be falsified but they can never be conclusively proved, as with the sock drawer thought experiment. He therefore proposed that falsification be used as a boundary condition for science, and consequently that anything that could not be falsified belonged to the domain of metaphysics. 

While the Logical Positivists held that metaphysics was meaningless because it could not be verified, Popper never suggested that because metaphysics could not be falsified it was without meaning. Rather, he recognised that metaphysical statements tend to imply beliefs, and therefore that anything in the realm of metaphysics is a matter for individual belief. Nothing could rationally force a change in such beliefs, at least in terms of definitely proving them false, but this was categorically not the same as claiming that such beliefs were meaningless.

By the time of Popper’s knighthood in 1965, Logical Positivism was widely recognised as having run its course, in no small part thanks to Popper’s contribution. 

Sadly for Popper, his position that falsification could be used as a boundary condition for science was quickly under attack. Thomas Kuhn and others observed that scientists do not abandon their theories in the light of contradictory evidence, which was a central assumption in Popper’s account, and Feyerabend (who had severe personal issues with his ex-mentor Popper) went on to demonstrate that there were no lasting boundary conditions to any human endeavour, never mind science.

However, this in no way invalidates the importance of Poppers work: Logical Positivism was a particularly vicious form of intellectual fascism and Popper’s contribution to its demise is to be commended and celebrated. Indeed, it is sad that despite the collapse of this school of thought in philosophy, echoes of its influence are still found in the tacit opposition certain prominent scientists and their supporters have for metaphysics.

The issue of how to present this viewpoint without seeming to be expressing solely my own bias gave me considerable pause until I received unlikely aid in the form of an article in The Oxford Companion to Philosophy on the topic ‘Metaphysics, Opposition to’ written by Prof. E. J. Lowe of the University of Durham. This hefty reference book has been a helpful tool in my philosophical investigations, but it is mostly written in such a dry and inaccessible prose that I never expected to find buried within its pages something as fiercely impassioned as the following extract: 

Opposition to metaphysics has come from both within philosophy and outside it. Logical positivism, though now defunct, was particularly hostile to what its adherents saw as the meaningless, because unverifiable, claims of metaphysics. These objections foundered on the impossibility of providing an acceptable criterion of verifiability. But the deference to empirical science displayed by the Logical Positivists is still a feature of much Anglo-American analytic philosophy, creating an intellectual climate inimical to the pursuit of speculative metaphysics… Such writers are often blithely unaware of the uncritical metaphysical assumptions pervading their works and the philosophical naivety of many of their arguments. But it is ironic that the deference shown by many philosophers to the latest scientific theories is not reciprocated by the popularizing scientists, who do not conceal their contempt for philosophy in general as well as metaphysics in particular. 

Professor Lowe seems to take some delight in exploring the specifics of opposition to metaphysics (both from systems of thought equivalent to Logical Positivism, and also from cultural relativism), and in doing so demonstrates that opponents to the field do not agree on even basic metaphysical tenets, thus allowing him to conclude:

The very fact of such widespread disagreement over fundamentals demonstrates the need for critical and reflective metaphysical inquiry pursued not dogmatically but in the spirit of Kant. 

Or to put it another way: since we do not agree, even on purportedly objective issues such as science, the need for metaphysics is amply demonstrated.

While Feyerabend was correct in asserting that there are no lasting boundary conditions to human endeavour, this does not preclude using Popper’s concept of falsification usefully. After all, the absence of lasting boundary conditions does not mean we cannot choose to erect boundaries wherever we wish. Indeed, if we agree to a particular boundary it may stand (by custom if by no other means) for as long as we wish. This, after all, is the basis by which one country distinguishes itself from another. 

Somewhere out in the metaphorical landscape of knowledge lies an almost insignificant stone marker reading ‘Erected at the boundary of Falsification’. It was set down by Popper to mark the end of science and the beginning of metaphysics. I suggest that even if we do not wish to use it to mark the border of science, Popper’s milestone can still be usefully interpreted as saying: ‘beyond this point lies metaphysics!’

Comments

[Peter Crowther]

I appreciate (and try to follow) Popper's comment that although it may not be possible to have a *rational* conversation about a metaphysical topic, it should nevertheless be possible to have a *reasonable* conversation about that topic. I apologise for the inevitable misquote as I'm at work and away from my own reference books!

[Tide]

Surprised you didn't mention anything about "The Open Society and Its Enemies". Some of it sits with me as another useful metaphorical boundary.

[zenBen]

Intellectual entrenchment always reminds me of watching insects fighting over small patches of the garden...

[Patrick]

I like the idea that there are no true boundaries between different domains of thought, such as science and metaphysics, or science and fashion, or metaphysics and sex. After all, isn't metaphysics just a way to try to get off with the universe (usually by pushing a wank cycle with seretonin and dopamine receptors)?

For instance, Bayes' theorem lines up Popper's whole worldview nicely as a special case of probabilities in general. You only need falsificationism for cases where the probabilities are really skewed, such as finding the white sock in the black sock drawer. The odds are 1,000,000,000,000,000:1 against, so Bayesian math isn't going to yeild a useful judgement criteria. Evolution is probably the same way, since its crucial moments depend on similarly infintesimal odds.

So you can falsify evolution, but you can't falsify creationism, or intelligent design, therefore they shouldn't even be in the same room together. Or, in a broader bayesian frame, you could say its possible theres an entity external to this universe that did indeed opt for one of the latter two (though it seems far more efficient to just evolve everything) - but the key is, there isn't enough information available to reasonably assing a probability to the existence of this exterior entity. The problem with religious people, and the precise technical reason why faith is contrary to rational thought, is that they believe God exists with a 100% probability, and assigning absolute certianty to any proposition breaks the zeroth rule of bayesian rationality.

Agnostics on the other hand, rather than being passive evaders of the whole debate, actively appreciate the need for more information in order to make rational judgements on matters from the huge (God et al.) to the mundane (invest in this company? will working on this project help my career?).

[Peter Crowther]

Ah yes, Bayes. I like the following pair of ideas:

"What's the probability of intelligent life evolving in this Universe? Infinitesimal, therefore there must have been a Creator."

"What's the probability of intelligent life evolving in this Universe, given that there is life in this Universe sufficiently intelligent to ask the question? Unity."

But note the following:

"What's the probability of a Creator existing, given that I speak with Him on a daily basis and see evidence for His wonderful creation all around me?"

[Patrick]

The first statement draws a causation from a correlation, just because it seems more likely that an intelligent agent is at work doesn't imply that this is indeed so. And when you take autopoiesis into consideration the odds aren't so infintesimal.

The second statement is a circular concept, perhaps a paradox, similar to the Liar's paradox (this statement is false) or the Epimenides paradox (the following statement is false; the previous statement is true). Bayesian reasoning is of a different form.

The third statement assumes a 100% prior probability, so yeah, you're going to get a big posterior probability from that. But a more realistic question is what is the probability that my daily conversations with god aren't just me talking to myself? You still need more information, which cognitive science has already made some strides towards, but which needs more study to make any meaningful distinctions. For instance, what if the Penrose hypothesis is true in a weak sense and quantum non-locality affects cognition, putting us in a subtle yet significant dialogue with "god" at nearly all times? Then we could draw a meaningful distinction between verbal conversations (which is probably just reinforcing psychological processes at a high level) and intuition (which may be a real quantum-guided cognitive phenomena at a low level). I'm just spitting conjecture here, not founding a religion or philosophy, and thats the point.

[Neil]

But, more importantly... How does someone who is Austrian-born, get to become "British"?

Or is that like a philosophical driver's licence? Proving that you can think out of and around the box...?

"Yeah, he's a real philosphical-type dude, look at his passport!"

[Chris]

Peter: if you can find that quote, I'd love to hear it!

Tide: I haven't actually read The Open Society yet - there are so many books to read and so little time! :) I felt that I should read Plato's Republic before The Open Society and Its Enemies (since it opposes it), but I have no great desire to read Republic since Plato's political philosophy seems so chilling... It leaves Popper's other work in a netherworld for me.

Now it may seem odd that someone so interested in philosophy has not read the "Greek classics", but I found in my own philosophical investigations that the Greek classics are all somewhat pointless when one is dealing with the problems of modern philosophy! :) Besides, I can't avoid absorbing much of the content of these early works from the work of other philosophers that reference it.

I'd love to hear what you gained from reading The Open Society though, if you have the time and the inclination.

ZenBen: Yes, I know what you mean. The behaviour of insects we are not likely to affect; I hope the same is not the case for entrenched intellectuals! :)

Peter/Patrick: the issue of God never reaches the domain of probability since one generally accepts or rejects the idea as an a priori assumption, as is implied here. :) As for Penrose, although I doubt his mechanism I find the idea of non-local consciousness to have enormous explanatory potential... of course, one can make the same claim about God. :)

Neil: Through the magic of immigration, naturally! (Or is that the magic of naturalisation, immigrantly?) :) Popper fled the Nazi regime to New Zealand and then came to Britain where our generous immigration policy granted him citizenship. :D I've got to get one of those special philosopher passports, though - very handy! :)

[Peter Crowther]

From Karl Popper "The Logic of Scientific Discovery" chapter 1 (on page 15 of the Routledge paperback I have):

"My criterion of demarcation will accordingly have to be regarded as a /proposal for an agreement or convention/. As to the suitability of any such convention opinions may differ; and a reasonable discussion of these questions is only possible between paties having some purpose in common. The choice of that purpose must, of course, be ultimately a matter of decision, going beyond rational argument.*5

"*5 I believe that a reasonable discussion is always possible between parties interested in truth and ready to pay attention to each other.

[Chris]

Thanks Peter! That quote reassures me that I haven't got my Popper mixed up, as well as putting forward the idea that reasonable discussion should always be possible provided there is a common purpose.

I gave my copy of 'The Logic of Scientific Discovery' to the husband of a work colleague when I was in London who once said to me that the Greeks had done all the important philosophy and that nothing worthwhile had happened in the field since then. :)

[Peter Crowther]

It's interesting to watch the evolution of that particular view, as the footnote was added by Popper some decades after the original text.

[translucy]

"to pay attention to each other" (especially during a debate of any importance) doesn't seem to be a strength in western europe, as far as i can see. Maybe Popper had the same impression...

[Peter Crowther]

I get that feeling, unfortunately.

[Ernest Adams]

I have always regarded Kuhn as sociology, not philosophy. Kuhn's observations on the *behavior* of *scientists* have no bearing on how science *ought* to be conducted or how truth should be sought.

Many, even most, disciplines exhibit distinct differences between theoretically correct approaches and actual practice, of which game design is a familiar example.

[Chris]

But such deontic issues as how things 'ought to be conducted' are not the sole concern of philosophy, of course. Kuhn may have been published as sociology but it's been sucked into the philosophy of science canon (anything can become philosophy, after all, given the right spin!) Personally, I'm enjoying having it there! :)