Letter to Common Sense Atheism VII

Dear Luke,

In your last letter, you wrote that before you could answer my questions, it was necessary to define the concept of “best explanation”. While I would have been fine with the concept of “the explanation that you find most convincing for whatever idiosyncratic reason the murky crevices of your psyche can produce to rationalize its decision”, I understand that you prefer “a model of explanation called explanationism that is intuitive to most people.”

x is the best explanation of y if it is the case that:

(A) if x were true, then by knowing x we would better understand y’s causal background than by not knowing x [i.e. x is a potential explanation of y],

and if it is also the case that

(B) x possesses the following explanatory virtues to a greater degree than any other known potential explanations of y: testability, consistency with background knowledge, past explanatory success, simplicity, ontological economy, informativeness, predictive novelty, explanatory scope, and explanatory power.

The problem with this definition by explanatory virtue is that some of the virtues cause you to artificially limit the investigation of the unknown by handcuffing it to the parameters of that which is presumed to be known. This all but guarantees systematic errors based on incorrect assumptions of the past. While it would certainly be ideal for a good explanatory hypothesis to be testable, but that is simply not possible in all cases. It therefore sets an artificial and incorrect technological limit on the process; for example, the x-ray hypothesis was correct regardless of whether it was possible to test for them.

Consistency with background knowledge is irrelevant. Fitting within a tradition of past success is similarly irrelevant. Simplicity is irrelevant too. This is philosophy, not interior design. Ontological economy begs the question of what is “necessary”; Occam’s Razor is a shortcut, not a reliable rule. On the other hand, informativeness is correct, predictive novelty is both applicable and useful, and explanatory scope and power are reasonable. I would give priority to informativeness, explanatory scope, and predictive novelty.

So, I am content to accept your explanatory model if you are willing to give priority to the three aformentioned explanatory virtues.

Best regards,
Vox

This was written in response to Letter to Vox Day VII.