William Kingdon Clifford: Reason’s Role in Faith Nicole Scott Free Inquiry

William Kingdon Clifford (1845–1879) was a brilliant mathematician and philosopher. He was the first to suggest the geometrical underpinnings of gravitation. Albert Einstein, a contemporary, developed his geometric theory of gravitation nine years after Clifford’s death. As a philosopher, Clifford was interested in and wrote about the mind and consciousness. Of principal interest to us here is his essay on faith, titled “The Ethics of Belief,”1 in which he argues that “it is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence.” According to Clifford, blind faith—i.e., belief without the support of adequate evidence—is immoral. Clifford’s position on faith was opposed by the famous philosopher William James in his “Will to Believe” lecture, delivered to philosophy students of Yale and Brown Universities.

Clifford begins his essay with a story: A shipowner, about to send a ship full of emigrants to sea, has doubts about the reliability of the ship, which is quite old. He manages to assuage his doubts (and dismiss troubling thoughts of an expensive overhaul) by considering that the ship has made many successful passages already and by putting his trust in Providence that the vessel will weather any storms this time as well. When the ship sinks with great loss of life, he collects the insurance. According to Clifford, the shipowner, given the evidence before him, had no right to believe. Then Clifford asks if the owner’s guilt would have been diminished if the ship had come through safely. “Not one jot,” he replies. It does not matter if he happened to believe something that is true. What matters is whether or not he had a right to believe it, for “the belief held by one man was of great importance to other men.” Now Clifford widens the field: “We have no choice but to extend our judgment to all cases of belief whatever.” He excuses no one: “No simplicity of mind, no obscurity of station, can escape the universal duty of questioning all that we believe.” He seems to modulate this idea later in his essay.

Clifford asks, “What would be thought of one who, for the sake of a sweet fruit, should deliberately run the risk of bringing a plague upon his family and neighbors?” He continues:

In like manner, if I let myself believe anything on insufficient evidence, there may be no harm done by the mere belief; it may be true after all, or I may never have occasion to exhibit it in outward acts. But I cannot help doing this great wrong towards Man, that I make myself credulous.

And what, one may ask, is the harm in making oneself credulous? Clifford explains: “The danger to society is not merely that it should believe wrong things, though that is great enough; but that it should … lose the habit of testing things and inquiring into them; for then it must sink back into savagery.”

Many people believe as they do because their faith has been passed down by their parents, and they have never bothered to look further. Clifford judges such people harshly:

If a man, holding a belief which he was taught in childhood or persuaded of afterwards, keeps down or pushes away any doubts which arise about it in his mind, purposely avoids the reading of books and the company of men that call in question or discuss it, and regards as impious those questions which cannot easily be asked without disturbing it—the life of that man is one long sin against mankind.

Ouch, I’ve been there. You? Surely not everyone who consciously and consistently dispels their own doubts commits “one long sin against humanity.” Surely sin requires an awareness of the immorality of one’s action. The indoctrinated are often advised to dispel doubts; it is sinful, they are told by religious leaders whom they trust, to entertain doubts about their religion. Those who buy into this proscription fall into a trap, from which extrication is not easy, but they do not sin, in my opinion.

As I made my way through Clifford’s essay, I became concerned that he applied his basic principle too rigidly. We live our lives in probabilities, not absolutes. Then, finally, with the following statement, he brings his demands on faith into the realm of the possible: “There are many cases,” he writes, “in which it is our duty to act upon probabilities, although the evidence is not such as to justify present belief.” Ahh, that helps. But then it’s back to business as usual for Clifford:

Inquiry into the evidence of a doctrine is not to be made once and for all, and then taken as finally settled. It is never [emphasis added] lawful to stifle a doubt; for either it can be honestly answered by means of the inquiry already made, or else it proves that the inquiry was not complete.

And he adds this powerful admonition to believers: “‘But,’ says one, ‘I am a busy man; I have not time for the long course of study which would be necessary to make me in any degree a competent judge of certain questions, or even able to understand the nature of the arguments.’ Then he should have no time to believe.” If humans came even close to implementing Clifford’s precept, church attendance would plummet. I wonder how many pastors would have to excuse themselves.

Clifford begins the second section of his essay with this question: “Are we then to become universal skeptics, afraid always to put one foot before the other?” Confident this will not happen, he offers this welcome explanation:

The beliefs about right and wrong which guide our actions with men in society, and the beliefs about physical nature which guide our actions in dealing with animate and inanimate bodies, these never suffer from investigation; they can take care of themselves without being propped up by “acts of faith,” the clamour of paid advocates, or the suppression of contrary evidence.

Next, Clifford asks in what cases human testimony is worthy of belief. His answer is that we must have solid grounds for trusting the veracity, knowledge, and judgment of our source. Mohammed, for example, may have been of high moral character, who spoke the truth as far as he knew it, but where is the evidence that he knew the truth? Also, the longevity of a belief is insufficient reason for accepting it. The belief may have been “founded on fraud” and “propagated by credulity.” The fact that Christianity has been around for two thousand years does not argue convincingly for its veracity. On the other hand, traditional human experiences provide a solid basis for our thoughts and actions. According to Clifford, these experiences give us “conceptions of right,” such as justice and beneficence. Clifford argues that these conceptions are instincts, not propositions. Still, he adds, it is our duty to verify any statements that emerge from our observation of the interaction of these instincts.

Finally, Clifford gives this general rule regarding belief in such things as reported historical events and alleged paranormal experiences: “No evidence … can justify us in believing the truth of a statement which is contrary to, or outside of, the uniformity of nature.” He continues, “If an event really happened which was not a part of the uniformity of nature, it would have two properties: no evidence could give the right to believe it to any except those whose actual experience it was; and no inference worthy of belief could be founded upon it at all.” If I apply that rule to the resurrection of Jesus (to take the central Christian miracle), I must say that, even if Peter saw the risen Jesus, I have no right to believe it. And although Peter may infer from what he witnessed that Jesus is divine, this inference is not worthy of my belief.

In an article in Free Inquiry, Frederik Kaufman explains Immanuel Kant’s thinking on the matter of belief formation:

To the extent that we believe on the basis of self-deception, wishful thinking, insufficient evidence, peer pressure, habituation, upbringing, familiarity, mere assertion, dubious authority, naïvité, or simple unquestioning faith, we fail to respect ourselves as persons. Sincerity of belief and depth of conviction are beside the point.2

In the debate between James and Clifford, Kaufman agrees with Clifford’s fundamental assertion: “It is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence.” If “suitably qualified,” Kaufman says, the assertion is correct. He explains: “Not all failures to believe [to ground one’s belief] on sufficient evidence are equally wrong.” He contrasts believing that it will not rain today with believing that global warming is no threat to humanity. As for James, Kaufman takes issue with his permission to believe whatever the intellect does not rule out. As do I.

In America today, it is commonplace to hear someone lauded as a “person of faith,” with no indication that the faith of the person so lauded is supported by sufficient evidence. Just “person of faith,” as if faith in and of itself deserves praise. It does not. The very foundations of our American democracy are being eaten away by rampant credulousness, whose roots can be found in the evangelical injunction: Believe in Jesus, and you will be saved. America needs to listen to Clifford: Thou shalt not believe on insufficient evidence.


[1] William Kingdson Clifford, “The Ethics of Belief.” In Religion from Tolstoy to Camus, edited by Walter Kaufmann. New York, NY: Harper and Row, 1964.

[2] Frederik Kaufman, “The Right to Believe,” Free Inquiry, December 2016/January 2017, Vol. 37, No. 1.

William Kingdon Clifford (1845–1879) was a brilliant mathematician and philosopher. He was the first to suggest the geometrical underpinnings of gravitation. Albert Einstein, a contemporary, developed his geometric theory of gravitation nine years after Clifford’s death. As a philosopher, Clifford was interested in and wrote about the mind and consciousness. Of principal interest to us …