Tuesday, March 13, 2012

The Problem of Justifying First Principles

Ann Arbor

I like the dialogue Defending Science: An Exchange, with Michael Lynch and Alan Sokal.

In the philosophical discussion re. "properly basic beliefs" two candidates for PBBs are: the laws of logic; and sense experience. In a recent nytimes dialogue NYU physicist Sokal provides support for these as PBBs. He writes:

"It’s hard to imagine what an ab initio justification of logical principles like modus ponens would look like. But I guess that I have never gotten much worked up over this problem: all of us who are interested in discussing more serious problems (be they in philosophy, science, mathematics, politics or anything else) have no choice but to use modus ponens (and a lot of other things).

Likewise for sense experience and for knowing what information, if any, it gives about the external world (though this is a much more serious issue in my opinion than modus ponens): solipsism and radical skepticism are irrefutable, as far as I can see, but that does not mean there is any reason to take them seriously. In practice no human being does — even philosophers stop being solipsists or radical skeptics when they are shopping for dinner."

Sokal states that our fundamental epistemic principles are "well-nigh universal among human beings."

Co-author Michael Lynch, a philosopher at U-Connecticut, agrees. He writes: "The relevant epistemic principles are fundamental precisely because any attempt to justify them is circular. (Think of trying to give a logical argument for trusting logic, or basic inference patterns like modus ponens). That problem doesn’t go away just because most people will accept certain principles."

Modus ponens is:

If p, then q
Therefore, q

Here we have unjustifiable beliefs we all hold as true. Plantinga, Alston, et. al. argue that, if Christian theism is true, then God-belief is probably properly basic as well.

Lynch writes:

"The problem of justifying first epistemic principles is very old. It led the ancient Greek skeptics to say that knowledge is an illusion. But over the centuries, it has been more common to draw a different conclusion, one concerning the relative value of reason itself. According to many people, what the problem of justifying first principles really shows is that because reasons always run out or end up just going in circles, our starting point must always be something more like faith.

There is a grain of truth in this disquieting thought. We can’t reasonably defend our trust in science just by doing more science in the hope of persuading those who aren’t already on board. But that doesn’t mean we can’t give reasons for our first principles, including the epistemic principles of science. Of course we can. The hard question is what sort of reasons we can give."