Mathew Iredale
In late 2004 the journal Nature announced the discovery of a new hominid species, Homo floresiensis (as discussed in issue 29's Sci Phi). This was, without exaggeration, one of the most extraordinary discoveries of the last 50 years. And yet within a short period of time, a number of scientists expressed misgivings about the find, arguing that Homo floresiensis was more probably a modern human suffering from microcephaly (a neurological disorder characterised by a malformation of the skull). This suggestion was quickly rebuffed by those in the “discovery” camp, but controversy returned earlier this year when an article in the journal Science again argued that Homo floresiensis was a human with microcephaly, a finding which was echoed by a different group of scientists writing in the journal Proceedings of the National Academy of Sciences . The articles attracted an immediate response from a number of palaeontologists, and, amid much media coverage, the disagreement soon descended into farce, with allegations of skulduggery and name calling.
At almost the same time as the Homo floresiensis debate was being reported in the media, another major scientific argument made the headlines, as the International Astronomical Union met to discuss whether Pluto should still be classified as a planet (following the discovery last year of a new planetary object slightly larger than Pluto). After several days of sometimes heated debate, the IAU voted to “demote” Pluto to the new category of dwarf planet. However, those in the media hopeful of another long running controversy were in for a disappointment, as the exact status of Pluto had been under discussion for over a decade and the change in status apparently came as little surprise to most astronomers.
Some scientific debates, such as the one concerning Pluto, are of short duration, but others can rumble on and on. Perhaps the longest running scientific debate is over the interpretation of quantum theory. There is, of course, an official interpretation of quantum theory, the so-called Copenhagen interpretation (formulated by Niels Bohr and Werner Heisenberg during their collaboration in Copenhagen in the 1920s). But although this may be the most popular interpretation amongst physicists, there are as many as ten other interpretations to choose from in the scientific literature. Clearly, we are still a long way from anything approaching a consensus.
But whilst it may provide the media with a few headlines, a lack of consensus is not something that worries science very much, a point made by a recent editorial in Nature in response to the Homo floresiensis stories: “Debate is something on which science thrives. Active disputes are signs of a discipline in rude health, in which discovery piles on discovery, each new fragment of knowledge questioning the one before, until sufficient findings accumulate to decide the matter one way or the other. ... In contrast, a field in which everyone blandly agrees with everything is a field in stagnation.”
Debate is also something on which philosophy also thrives, and it would most certainly stagnate if everyone blandly agreed with everything.
“Not much chance of that,” is the obvious reply. Philosophers agreeing with each other? Whatever next? But this, joking aside, is the problem. Whilst there is debate in science, there is also consensus. But the extent to which consensus exists in philosophy is itself debatable.
Consider free will. In the mid and late 20th century one could easily have got the impression that a consensus was emerging over the nature of free will. More and more philosophers appeared to agree that we have free will, and that this freedom is compatible with our decisions being causally determined (what is termed a compatibilist conception of free will). But then in the 1980s and 90s there appeared a number of robust defences (most notably by Randolph Clark, J R Lucas & Robert Kane) of the libertarian position; that free will is real but not compatible with determinism. At the same time, several books and articles were published (by Galen Strawson, Ted Honderich, Richard Double and Bruce Waller) criticising compatibilism and libertarianism. Any impression of a consensus was clearly illusory. In fact, in the free will debate we now appear to be in much the same situation as we were 50 or even 100 years ago.
It is no wonder that some philosophers have become exasperated with the whole situation. Ted Honderich clearly expressed this feeling when he wrote that if either one of these two “so overridden and wearied nags” (compatibilism and libertarianism) were really right then one of them would have proved it by now and plodded “at last into the winner's enclosure.”
Free will is just one example, of course, but it is not atypical. Unlike in science, debate in philosophy does not naturally lead to a consensus. In philosophy, we do not have discovery piling on discovery, each new fragment of knowledge questioning the one before, until sufficient findings accumulate to decide the matter one way or the other. Rather we have argument piling on argument, each new fragment of knowledge questioning the one before, but with little accumulation of findings to decide the matter one way or the other.
The philosopher Nicholas Rescher has argued that disagreement arises in philosophy because of “aporetic clusters”. An aporetic cluster is a set of related theses, each of which we have good reason to accept, but which are mutually exclusive when taken together. To return to the free will example, Rescher provides the following example of an aporetic cluster:
1) All events are caused.
2) If an action issues from free choice, then it is causally unconstrained
3) Free will exists – people can and do make, and act upon, free choices.
Rescher argues that there are good reasons to accept each of 1, 2, and 3, but one cannot consistently accept all three. The common reaction is therefore to accept two of the three premises and reject the third. Compatibilists accept 1 and 3, but deny 2; libertarians accept 2 and 3, but deny 1; and those who reject both positions may accept 1 and/or 2 but deny 3.
According to Rescher, most philosophical debates fit the model of the aporetic cluster; philosophical problems arise because commonsense fundamental beliefs are inconsistent.
Are we doomed, then, to endlessly debate philosophical problems without any hope of resolution? Well, perhaps we are, but so what?
This is one possible reply, anyway; that consensus is not the point of philosophy. The journey is more important than the finish line, in contrast to science, where the finish line is clearly the goal – discovering a new elementary particle or finding a cure for some debilitating disease – no matter how fascinating the journey.
But surely there must be at least a hope of reaching a consensus of some sort? Progress must be seen to be made to some extent otherwise how can we differentiate between professional philosophy and playground chatter of the “my dad is bigger than your dad!” sort? Scientists can answer the dispute empirically – get the two dads side by side and let's see who is bigger.
But philosophy does not have this option (unless it utilises science, of course). How, then, do we decide who has the bigger dad? Is there in fact a way to decide or is philosophy doomed to eternal debate, always travelling, never reaching the finish line, except in those rare cases when it is helped across the line by science?
Suggested reading
Philosophical Reasoning: A Study in the Methodology of Philosophizing , Nicholas Rescher (Blackwell)
Everything you'd ever want to know about Mathew Iredale is at www.mathewiredale.info.
