Steve, interesting post. I am a longtime lurker, this is my first comment. Thanks for the great work you and the other T'bloggers do, this is a daily stop for me in my continuing thirst for knowledge.
It seems as if the antirealist position is somewhat influenced by Hume-like skepticism? My position more closely reflects the thoughts of Thomas Reid, who said "I resolve to take my own existence and the existence of other things upon trust". The trust Reid speaks of is not based on his own reasoning or sensory experience, but is based on his faith in God:"...that God intended that a great and necessary part of our knowledge should be derived from experience". How does that agree or disagree with the antirealist position?
There are, as you know, a variety of realisms and their antirealist counterparts, viz. modal realism, moral realism, alethic realism, direct realism, scientific realism, &c.
A man can be a realist in one respect, but an antirealist in another.
Christianity commits a believer to certain forms of realism, viz. that God-talk has an extramental referent.
Reid represents one approach to philosophizing. What’s our starting point? Do we start with scepticism? Do we start with difficulties?
Or do we start with common sense? Do we start with what we all take for granted, and work back from there?
I agree with Reid on his prima facie confidence in perception, induction, memory, testimony, and other suchlike. I agree with where he affixes the burden of proof.
I agree with his distinction between paper doubts and palpable doubts.
Sceptical thought-experiments are useful limiting-cases on what we can prove. But they should not frame a theory of knowledge.
Rather, we should begin with successful examples of perception, induction, communication, memory, &c, and reason in reverse to the necessary and sufficient conditions which make successful examples a success rather than a failure.
But I do have a couple of caveats:
1.As you know, Reid did more than mount a default argument for common sense, in the absence of a viable alternative.
He also grounded common sense in natural theology.
The problem with evolutionary epistemology is that it withdrawals the preconditions of rationality.
At that point, common sense loses its prima facie license.
Of course, that’s not so much a problem for common sense as it is for evolutionary epistemology.
2.Having conceded that our senses are generally trustworthy sources of information, this generic concession does not, of itself, answer the specific question of what our senses are reliable for. What information can we acquire via the senses?
By way of answer:
i) Everyone excepting the naïve realist (who is more of a hypothetical construct than a real person) will admit some discrepancy between appearance and reality.
I don’t think our senses are designed to tell us what the sensible world is like. I don’t think they’re designed to tell us if grass is really green.
ii) I think our senses are designed to let us navigate a physical environment and effectively manipulate our surroundings.
That, however, doesn’t require a transparent correspondence between what we perceive and what the sensible is like.
All it requires is a correlation between the external object and our perceptual token.
For example, when I withdraw money from an ATM, I punch commands into a keyboard. I’m not in direct contact with the money. I don’t see the money. All I see is the keyboard. What makes it work is not a correspondence between what I see and what I receive, but a correlation between certain encoded commands and the greenbacks.
iii) I also think our senses (especially sight and hearing) are designed to process propositional information. Thoughts encoded in words (whether spoken or written) and pictures.
Here there is a point of correspondence, but between one thought and another thought. A mind communicates an idea to another mind via a public medium of some sort.
3.But for several reasons I regard scientific theories as useful fictions:
i) Besides the reasons I’ve already given, perception is variable. The sensible world presents a very different appearance to a bee or bat or bloodhouse or hammerhead shark than it does to a man because these creatures have a sensory acuity which is attuned to different frequencies (as it were).
Which percept is correct? Well, they all are. Nature presents more than one appearance, and your sensory apparatus will select for a particular appearance.
ii) That’s somewhat subjective or epistemic, but there’s an objective or ontological dimension to this as well.
It’s not just one’s perception of the sensible world that’s variable. The sensible world is variable.
If I were an x-ray instead of a man, the spatial configuration of my world would be completely rearranged. Different walls and doors (as it were).
A different body density selects for a different configuration of barriers and open spaces.
Which is the real world? They are all aspects of the real world. It just depends on which “channel” you’re on (as it were).
4.How does my philosophy of science affect scientific arguments for the existence of God and other suchlike? It depends.
i) Due to the veil of perception, I don’t believe that we can reconstruct the distant past and—to take one example—finger the flood mechanism.
Likewise, I also don’t believe in a cosmological argument based on the latest version of the Big Bang.
There are too many intervening layers between the percipient and the external world to cut through.
ii) On the other hand, this, if anything, enhances certain versions of the teleological argument.
Back to the ATM. The more oblique the relation between appearance and reality or cause and effect, the more complex the relation. You need a designer to coordinate these intricate correlations.