Just the Facts, Ma'am

The Great Urban Legend Of Our Time

Evidentialism is the doctrine that demands everything one believes must be adequately grounded upon evidence. If no evidence, then belief is irrational.  Whenever we come across such sweeping, grandiose assertions, we find ourselves driven to ask, "By what evidence does that assertion hold true?"  Pray, what is the evidence for evidentialism?  Eerrrr.  Ummmm.  More time, please.

David Berlinski is on to it when he writes:

It is wrong, the nineteenth-century British mathematician W.K. Clifford affirmed, "always, everywhere, and for anyone, to  believe anything upon insufficient evidence."  I am guessing that Clifford believed what he wrote, but what evidence he had for his belief, he did not say.  [David Berlinski, The Devil's Delusion: Atheism and Its Scientific Pretensions.  (New York: Basic Books, 2009), p. 47.]

Fast forward to the Great Collider in Europe.   Naturally, this Collider is most famous because it is the biggest.  Twenty-seven kilometers of underground tunnel to house the great beast--all in an effort to research the tiniest particles in matter.  The biggest to find the smallest.  Looking for evidence.  So that the evidentialist can believe.   But what constitutes evidence?  Instantly, the "picture" becomes exponentially more complex, and less evidential, we may say.

A neutrino by itself cannot function as a reason  for my belief.  It is a subatomic particle, for heaven's sake.  What I believe is a proposition, and so an abstract entity--that neutrinos have mass. . . . The neutrino, together with almost everything else, lies at the end of an immense inferential trail, a complicated set of judgments.  [Ibid. p. 49.]

We have been treated over recent decades to the wondrous spectacle of scientists sitting in rooms "observing" what is taking place in the depths of the Great Collider.  Then, for a nano-second, a blip appears on a computer screen, then goes.  The audience claps loudly.  Eureka.  A neutrino!  A quark!  A Higgs bosun!

The immensity of the inferential trail is instantly forgotten, if ever remembered.

Believing as I do that neutrinos have mass--it is one of my oldest and most deeply held convictions--I believe what I do on the basis of the fundamental laws of physics and a congeries of computational schemes, algorithms, specialized programming languages, techniques for numerical integration, huge canned programs, computer graphics, interpolation methods, nifty shortcuts, and the best efforts of mathematicians and physicists to convert the data of various experiments into coherent patterns, artfully revealing symmetries and continuous narratives.  The neutrino has nothing to do with it.  [Ibid., p. 49.]

If you ever have the awkward misfortune to talk to an evidentialist, ask him if he believes in neutrinos. He will, of course, insist that he does.  "Really", will doubtless be your rejoinder.  "What is your evidence for such a strange belief?" It is at this point, evidence, that long nursed-to-the-bosom comfort blanket of Unbelief, gets snatched away by the nasty Lucys of this world.  As Berlinski mischievously puts it:

Within mathematical physics, the theory determines the evidence, not the other way around.  What sense could one make of the claim that top quarks exist in the absence of the Standard Model of particle physics?  A thirteenth-century cleric unaccountably persuaded of their existence and babbling rapturously of quark confinement would have faced then the question that all religious believers now face: Show me the evidence.  Lacking access to the very considerable apparatus needed to test theories in particle physics, it is a demand he could not have met.  [Ibid., p.50]

Believing on the basis of evidence is a simplistic nostrum.  Evidentialism is a crock.  It shapes up as the last refuge of the scoundrel, or the fool.