This week I had the pleasure of listening to my friend Noah appear on EconTalk to discuss the status of economics as science with my former professor in that discipline, Russ Roberts.

I would characterize neither of them as epistemologists or philosophers of science, but perennial practitioners. The chief difference between them, other than age or Noah’s ability to draw on a knowledge of physics as well as economics, is one of faith.

Noah himself brought this up: all science requires a leap of faith somewhere, as he put it. The example he used was Galileo’s experiment demonstrating that two balls of different mass will fall at the same rate. There’s only so far you can go to prove that this represents a universal law, or even a very general one. What if it only applies in our part of the universe? What if it only applies when there is a human observer?

Noah isn’t saying this makes us helpless or that we have to willfully ignore such thought experiments—nor should we.

The arc that Russ Roberts has gone through on this subject since I took his class during the crash in 2008 to the present can be characterized as a loss of faith—rather than the embrace of a given intellectual framework.

Russ has become unwilling to make that leap of faith when it comes to economic methods and arguments. But more importantly, he has lost faith in the sense of trust—trust in his fellow economists. Most importantly of all, he has lost faith in his own judgment.

The questions that he seems to come to again and again—why economists can’t agree on the effect of the 2009 stimulus, whether any study has ever completely won over people whose perspective was at odds with its conclusions—are attempts to establish, or prove once and for all the absence of, the credibility of economics as a field.

I’m not sure there’s an answer that could satisfy him. There’s a certain self-fulfillingness to losing trust in this way, much as widespread generosity in granting trust seems to perpetuate itself. How such trust can get established in the first place is a mystery, one that I’m certainly not going to get to the bottom of in a blog post.