For the purpose of this question let 'belief' mean anything a person accepts to be true for whatever reason - in particular if someone 'knows' something they also 'believe' in it.

I read this old discussion in Philosophy.SE chat and this inspired me to write this question.

As far as I understand:

  • Hitchens (and possibly other New Atheists) define faith as belief without evidence, theism as a doctrine rooted in faith, atheism and anti-theism as indifference to / rejection of arguments derived from faith.
  • Hitchens (and other New Atheists) reject and oppose all arguments that are derived from faith (under the above definition of faith).

However, is it even possible to believe in anything without ultimately deriving this belief from faith alone?

  • Did Hitchens personally research the Big Bang? The theory of evolution? The theory of relativity? Any other scientific theory? If not, he must be basing his beliefs in these theories in the evidence produced by other people. Then he must trust these people. What is his evidence that he hasn't been lied to?

But let us ignore the above point and assume that the knowledge of all people is shared and therefore what is evidence for scientists personally researching a given topic is also evidence for all other people. This leads to the following even more important problems:

  • Deriving beliefs from evidence assumes that evidence can point to truth. Yes, one can argue that evidence itself points to the ability to derive knowledge from it, since historically depending on evidence has been fruitful in various areas of inquiry. But this is circular. Therefore the belief that knowledge can be derived from evidence is either based on faith or circular?
  • Beliefs can be either founded on evidence or on faith. But as per the above point all beliefs founded on evidence are founded on faith. Therefore, all beliefs are founded on faith?

Does it mean that - as per Hitchens' definition of theism and atheism - everyone, even Hitchens himeslf is a theist while there are no atheists? (Barring people who don't believe in anything, but is this even possible?)

Am I correct that all beliefs are ultimately founded on faith or have I made an error here?

  • Hitchens et al. do not "define" faith this way. Even when they phrase it this way it is just a vague shorthand slogan meant to point to something the audience is already familiar with, and give it a negative connotation. What they really mean is more a type of belief one would not easily give up even when on purely rational/empirical grounds they should.
    – Conifold
    Commented Sep 30, 2021 at 20:55
  • 2
    You could say that, in these sense that no position can be completely free of unproven assumptions. The "web of belief" can never be definitively anchored. But this is not what is generally meant by "faith," which would be a belief held in the face of contrary evidence. And your implication is overly broad. There are many standards for evaluating evidence, factoring out bias, discerning contradictions, forming consensus, and otherwise judging well-founded beliefs in contrast to faith and authority. Commented Sep 30, 2021 at 21:58

5 Answers 5


I'll say up front that it is foolish to enter this particular debate without acknowledging that almost all lines of argument therein are deeply and inherently prejudicial. People like Hitchens are not neutral, curious philosophers seeking out deeper understanding; they are pundits with a definite political agenda, largely incapable of working with (much less accepting) statements that might erode any portion of their pre-given worldview. This topic is trench warfare, not a gentleman's duel, and no one involved takes kindly to those who try to span the gap.

That in mind, I find myself compelled to discount Hitchens' definition of faith, as it seems a bit shaded. Faith is belief that aligns with a given moral worldview. It is an ought statement, not an is statement, so the concept 'evidence' doesn't apply in the way Hitchens intends. When viewed in that light, however, it isn't quite fair to say that scientific beliefs are based in faith, because scientific beliefs do not generally conform to any moral worldview. I'm not suggesting there is no scientific worldview per se, merely that science does not establish a moral ought in the way that other worldviews do.

There are a number of people who advocate for science (Hitchens being one of the foremost), but advocating for science is itself a moral worldview: an assertion about how the world ought to be, not how it is. It would be fair to suggest that these beliefs are faith-based, even if science itself is not.


The answer above does not take a philosophical approach, so I'll try.

In this context, it seems to me that in the case of Did Hitchens personally research the Big Bang? what you should be thinking about is that has the evidence for that belief has been accumulated in a scientific fashion? That meaning, whether the evidence went through the scientific method in its recognition as "evidence".

That being said, I still disagree with Hitchens.

The ultimate question of existence arrives at: "Ok, physics exists. Why?" And the answer to that question leads to the ultimate faith question of whether it is an intentional beginning or not.

If anyone has a truly atheist answer to the question of what makes physics possible, I would be compelled to listen.

Furthermore, you may reject the claim that the scientific method is a valid way to claim something to be "evidence", but I think at that point you reject a major part of western thought, so it would be a pointless debate.


TLDR: 1 yes, unsupported assumptions are necessary to establish knowledge. 2 this is not "faith" as the word is usually used in religious debates.

What you are describing here is the Munchausen trilemma, the idea that in order to prove anything, to justify any knowledge, our set of proofs must be either:

  • circular
  • infinite (a case you don't mention, but is just as annoying as a circular set)
  • end up at some point on unjustified assumptions (which you call faith)

Although I think it is true that we need a set of trusted assumptions at the base of any knowledge (but some others are fine with circular or infinite proofs), it is misleading to equate this trust with the concept of faith as it appears in the religious/atheists debate.

Trusted assumptions are subject to revisions, as has happened often in the history of science (see the concept of paradigm shift ) when new facts are observed that are incompatible with the so far accepted bedrock of assumptions, those are criticized, discarded if necessary and replaced.

Such an attitude is not compatible with faith as religious people use the word. Someone who would admit to be ready to discard their belief in God if faced with evidence would never be considered to have a strong faith.

We have plenty of beliefs that are unsupported by evidence. For example, I believe I have been raised by my biological parents although we never took a DNA test and I don't remember anything of the first few years of my life. Yet, if I was presented with evidence of the contrary (for example the aforementioned DNA test, and some assurance that it is not forged, not a error) I would readily admit that I was wrong.

On the other hand, we have people that still believe the flood happened as described in the Bible a few thousand years ago despite massive amounts of evidence that it didn't.

More than a mere belief without evidence, faith is caracterised to be a belief that resists to contrary evidence. The faithful belief is central, and evidence is interpreted so that it can remain unchanged, which makes it a very specific kind of belief. And this is not necessary for establishing any knowledge.


The main point to take into account is that belief and faith are psychological conditions. Belief is more or less certain and many of our beliefs are very uncertain, in particular because they are revisable. I believe, without being certain, that my neighbour is an honest fellow, but I wouldn't be too surprised if I learned that he didn't declare all his revenues to the taxman. I would accordingly revise my belief, still without absolutely be certain because, who knows, he might have had an honest reason to fail to declare all his income.

Many beliefs are revisable because they are based on empirical evidence. New empirical evidence leads to a revision of some belief.

Faith by definition is a belief of maximal certainty. However, even faith is revisable, at least for many if not all believers. Different believers will have very different species of faith. Some people may have some metaphysical reasoning implying the existence of God, while others may have gone through some sort of psychological incident leading them to believe they have met God in person, so to speak. Ultimately, everybody starts from some evidence. The question is whether different species of faith are revisable. I suspect all are, but not necessarily in the same circumstances.

Science can be seen as professional rationality, that is, rational people working hard, in cooperation, professionally, to achieve the most plausible belief. The Big Bang is a belief but a highly revisable belief. Thus, it is fallacious to put belief in God and belief in the Big Bang on a par. Very nearly every scientist who believes in the Big Bang will revise his belief if good empirical evidence became available.

Good empirical evidence here means something every specialist could verify by himself, if only in principle. Anything comparable for a belief in God? I don't think so. Many believers will keep believing in God no matter what. Recently, many believers have left the Catholic Church because the long and protracted sexual abuse scandal which still has no satisfying resolution, yet, many of these people will still believe in God. I suspect that this is essentially out of desperation, for it makes perhaps life easier to live if you believe in something positive as a good God probably is. Thus, no amount of empirical evidence will make them change their mind and revise their belief. However, this in itself is a personal matter irrelevant to the metaphysical debate about the existence of God.

In this context, I don't think belief in God could be motivated by good empirical evidence as defined here. People believe in God because they want to believe in God, and they want to believe in God for reasons that have nothing to do with good empirical evidence. This may be the best definition of faith. There is a continuum between scientific belief and many believers' faith to the extent that their faith is revisable. So, many, but not all and probably not even most believers' faith. So, essentially, comparing the to is fallacious, specifically the fallacy of equivocation, because not all faiths are equal and not many faiths are based on good empirical data.


Yes, they are. But that is also irrelevant.

  • Belief is when you assume something about reality, then you have a belief about reality

  • Knowledge is when that belief can shown to be correct, through evidence

  • Faith is when that belief has no evidence, but you still keep trusting it to be accurate.

Side note...

However, is it even possible to believe in anything without ultimately deriving this belief from faith alone?

This gets things backwards; you do not derive belief from faith.

All faith is belief. All knowledge is belief.

Not all belief is faith. Not all belief is knowledge.

The discriminator is evidence. If you have evidence for your belief, the belief is knowledge.

Using this dictionary, we can deal with this:

Did Hitchens personally research the Big Bang? The theory of evolution? The theory of relativity? Any other scientific theory? If not, he must be basing his beliefs in these theories in the evidence produced by other people. Then he must trust these people. What is his evidence that he hasn't been lied to?

This is all true.

I could also be a Brain In A Vat.

Do I have evidence that I am not a brain in a vat?

No, I do not.

But here is the kicker: do I care if I am a brain in a vat or not? Does the Problem of Hard Solipsism concern me?

No, it does not. And it also did not concern Hitchens.

Instead he — and I — make it an axiom that we are not a brain in a vat. Sooner or later, we have to make such axioms, because — just as Feynman used to say — ask "Why" enough times, and you will run into a "We do not know". We have to take things as read eventually; as axioms.

So the question becomes: is an axiom equal to faith?

Using the definition above, yes it is. It is an assumption for which there is no evidence.


That is also wholly irrelevant to the question, because what Hitchens is talking about — when he says he rejects faith as a basis for ethics and morality — has nothing to with statements of the sort "I assume I am not a brain in a vat".

Using strict logic, the answer to the question is "yes", all knowledge is — ultimately — based on assumptions that cannot be shown any evidence for.

But practically speaking, the answer is "no", because axioms such as "I am not a brain in a vat" are not considered "faith". They are instead — universally — considered knowledge. Such axioms are simply not up for debate, at least not in the theism/atheism discourse.

Philosophers can have fun with such axioms — and consider them faith if they like — but for all practical purposes, they are knowledge.

So, when Hitchens says he has knowledge that for instance the Big Bang is a real thing, is he using faith when he trusts books and other people?

For purposes relevant only to formal logic: yes

For practical purposes, using axioms of the sort that are needed in order to assume we are real and not a brain in vat: no

  • 1
    Sure, the question is pretty bad (a confused version of Agrippa's trilemma). But this answer is even worse. It does not even try to engage with the issues and instead just asserts exactly what was the target of the OP's skepticism: We have no evidence that evidence gives reason to think a belief is true. And even if we had, it would be circular. So do we believe in the power of evidence by faith or is it some unexplained “custom” that we value evidence? This must be answered. It is the compulsory part of the question that any on-topic answer must address.
    – viuser
    Commented Sep 30, 2021 at 23:56
  • @viuser Answer expanded
    – MichaelK
    Commented Oct 1, 2021 at 8:25
  • @MichaelK "All knowledge is belief" Certainly not. You are redacting the definition of the word "knowledge". By definition, what you know is true, whereas what you believe may be true and may be false. Commented Oct 1, 2021 at 10:38
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    @Speakpigeon "By definition, what you know is true, whereas what you believe may be true and may be false." That is perfectly in line with what I write in the post.
    – MichaelK
    Commented Oct 1, 2021 at 13:37

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