Scientific presuppositions are about leaving certain philosophical debates to philosophers by assuming common sense answers instead of expecting scientists to either:
1) Solve these debates for philosophers, or...
2) Conduct scientific inquiry in a way that doesn't take sides.
That second option might seem fair and reasonable, but we're talking debates like:
- Does anything exist outside of our minds?
- If event A happens a million times in a million opportunities, is event A more likely than not to happen at the next opportunity?
- If multiple explanations can fit the facts, is it ever reasonable to prefer one over the other?
If multiple explanations can fit the facts, is it ever reasonable to prefer one over the other?
Your cellphone has gone missing. One explanation might be that you put it down somewhere and forgot about it. Another explanation might be that a team of foreign spies stole it while you were in the shower. Yet another explanation is that a time traveling alien collected it for a museum.
All three explanations fit the facts. As far as purely deductive logic goes, there is no reason to prefer one over the other. Yet we aren't paralyzed with indecision every time someone points out an outlandish, alternate explanation that could possibly be true. We prefer simple and ordinary explanations.
Remember the problem of underdetermined theory from last time? Same thing. It may be possible to think of outlandish alternatives for any set of observations, but it's inconsistent to let this paralyze scientific inquiry if we accept the notion of explanation-preference in general.
If event A happens a million times in a million opportunities, is event A more likely than not to happen at the next opportunity?
To reuse an example, suppose you have a small bag of marbles from which you keep drawing one marble, checking its color, and putting it back into the bag. After a million times, every drawn marble has turned out to be red. Is the million-and-first marble more likely to be red than non-red? Nearly everyone would answer 'yes!' because we think repeated trials count for something. Maybe not certainty, but surely they count for probability, right?
Or consider traffic lights. We trust that traffic light controllers are reliable enough that a green light on our own street almost certainly means a red light on the cross-street.
Yet Karl Popper's falsification only view of scientific learning denies any probability-increasing role for repeated results.
Does anything exist outside of our minds?
I don't need to explain how strongly we assume things exist outside of our own minds, which is why I find the popularity of Thomas Kuhn's incommensurable paradigms portrayal of science so puzzling (pun intended)!
If you'll recall, Kuhn portrayed scientific progress during normal periods as being judged against a set of puzzles scientists happen to be interested in at the time. After a paradigm shift, the puzzles and the way of judging can be so radically different there is no way to say science has progressed overall.
But if there is a mind-independent reality, we do have something to serve as a 'common measure' for scientific beliefs across history. Progress is a matter of how true these beliefs are.
A Fundamental Assumption
The physical world is orderly and comprehensible.1This may be the only basic presupposition (or pair of presuppositions) science needs. It implies a world 'out there' which we are capable of understanding. This wouldn't be possible if our senses were utterly unreliable, or if past experience didn't count for anything, or if every logical possibility were on equal footing.
Taking Aim at Science
If a philosopher questions science's ability to get at the truth, the first thing to do is ask whether the presuppositions above are being challenged. If so, then science is not the primary thing under attack.
Science begins with the presumption that the physical world is comprehensible to us [....] Therefore, any argument that assays to take down common sense and thereby to establish radical skepticism is simply outside science's purview. Science has many theoretical and practical tasks, but refuting skepticism is not one of them. A legitimate attack on science's rationality must target science alone, not science and common sense both.2So while science does require presuppositions, they aren't controversial ones. In fact, failing to make these basic assumptions would be far more questionable. Gauch sums this up neatly with his 'reality check':
Moving cars are hazardous to pedestrians.3Do you accept this statement as objectively true and knowable? If so, you already accept the kind of mundane assumptions science needs to get started.
1. Gauch, H. G., Jr. (2006). Scientific method in practice. Cambridge: Cambridge University Press. p. 138
2. ibid. p. 106
3. ibid. p. 134