Sunday, November 27, 2011

How do we know what we know?

After we came out of the church, we stood talking for some time together of Bishop Berkeley's ingenious sophistry to prove the nonexistence of matter, and that every thing in the universe is merely ideal. I observed, that though we are satisfied his doctrine is not true, it is impossible to refute it. I never shall forget the alacrity with which Johnson answered, striking his foot with mighty force against a large stone, till he rebounded from it -- "I refute it thus." [Boswell: Life of Samuel Johnson]
Tom Gilson summarizes the thesis of Alvin Plantinga's new book in the title of his review: "There’s No Good Argument For Design, But Who Needs One?" His description of Plantinga's argument reminded me of the exchange between Boswell and Samuel Johnson quoted above. Gilson on Plantinga:
.... Plantinga’s specialty is in epistemology, the philosophical study of how we know, and how we know that we know. He applies this to the question of whether we can know that nature is intelligently designed, just by examining it. Following detailed and rather technical discussions....he concludes that the arguments in favor of design are not compelling. ....

That argument swings both ways, of course. If Plantinga is right, and if there is no good argument for God in nature’s design, there is also no good argument against God in nature. Plantinga mentions that in this context but he does not dwell much on it. ....

...[I]f there is no design argument, does that mean no design, and no designer? No. For Plantinga it’s much simpler than an argument. Design is just apparent in the world. We can see it, as we can see that the world wasn’t created intact in its current form just five minutes ago, that our memories are at least somewhat trustworthy, that there are other people (other minds) in the world besides ourselves. No argument could prove these things true, yet we know them trustworthy knowledge regardless. These are “basic beliefs:” things we know without having to call upon a string of inferences to support that knowledge.

We can see design just as clearly, says Plantinga.
The same goes if you are on a voyage of space exploration, land on some planet which has an earth-like atmosphere, but about which nothing or next-to-nothing is known, and come across an object that looks more or less like a 1929 Model T Ford. You would certainly see this object as designed; you would not engage in probabilistic arguments about how likely it is that there should be an object like this that was not designed.
(The emphasis is added.) Of course Plantinga knows that perception of this sort can be mistaken. He goes on to analyze ways we can judge whether it is mistaken.... [more]