Over the last several days I have launched several important charges against Richard Dawkins' letter to his daughter . These critiques have been, for the most part, simply ignored by the many enthusiasic Dawkins apologists who have lept to his defense this week. So I am going to slow right down and lay out a fundamental critique more fully.
I will do so by focusing on Dawkins' epistemological proposal as it occurs in the letter. In this article and those following I'm going to list statements drawn verbatim from Dawkins. I will letter these statements [(A)...]. In addition, I will paraphrase these statements in my summary statements marking them with numbered propositions [(1) ...]
We will begin in this article with the scope and foundational claim of Dawkins' epistemology. Next, I will critique it with respect to the problem of infinite regress. Then in subsequent posts I'll focus on the problems of self-referential defeat and the falsity and arbitrariness of his claims.
Dawkins' evidentialist epistemology
Dawkins lays out his epistemology (his theory of knowledge) in the introductory section of his advice to his daughter. And this advice provides the framework against which everything else is understood. Thus, it is of pivotal importance and will occupy our attention here.
Dawkins begins with a question for his daughter:
(A) "Have you ever wondered how we know the things that we know?"
Now we need to be clear on the extent or scope of this statement. Dawkins is not asking how we know some things, e.g. facts about the natural world or the facts of natural science. Rather, it is a sweeping, comprehensive question: how do we come to have knowledge simpliciter? Consequently, any attempt to narrow the scope of Dawkins' remarks to one subset of our knowledge (e.g. to claim he is only talking about science) is simply inconsistent with his own stated focus.
With that in mind how does Dawkins claim we know the things we know? Dawkins answers with several statements. We'll consider the first here:
(B) "The answer to these questions is 'evidence'."
We can summarize (A) and (B) together as follows:
(1) "We know that p is true (where p is any statement) if and only if we have evidence for p."
That is Dawkins' first claim. And already a fatal problem looms.
An Infinite Regress
Dawkins' core claim is fundamentally flawed for a very basic reason: it leads to an infinite regress. In other words, it initiates a regress of appeals to justification or evidence which is infinite ... it never ends. Since an actual infinite cannot be traversed through successive addition (particularly one of this type!) it would follow that we could never satisfy the evidentiary demands for even one claim to knowledge.
[Summarized succinctly: In order to believe p I appeal to the evidence of p-1. But then to know p-1 I need to have further evidence p-2. And to know p-2 I need to appeal to further evidence p-3. And so on. So to know even one thing I would need to appeal to an infinite regress of evidences.']
Consider as example, belief in (1). How could Dawkins' daughter know (1) is true? In order to know this, she'd have to have evidence for (1). For instance: (1-1) "Daddy is smart and he says (1) is true." But then according to (1) Dawkins' daughter would need evidence for (1-1), such as (1-2) "I heard Daddy say (1) is true." And then she'd need to appeal to something like (1-3) "I usually hear correctly." And on it goes. For any evidence, summarized by a statement, Dawkins daughter would need further evidence summarized by a further statement.
Of course this only follows if (1) is true.
Since, as I said, we cannot traverse even one infinite regress of justification then we could know nothing if we accept that (1) is true.
That's the problem. Let's consider some rebuttals based on some of the comments I've read this week.
There's a philosopher's trick somewhere
I've heard this (with respect to the companion charge of self-referential defeat). All I can say is show me what you mean by a "trick". There is no trick here. (1) leads to an infinite regress and the skeptical consequences of infinite regresses in epistemology are well established.
The "But the letter is for a child" defense
I've heard this too. Apparently it is okay to say indefensible statements if you're saying them to a child.
But this is false. I agree that we need to be age appropriate. But if a child is old enough to understand the statement "All knowledge requires evidence" that child is also old enough to understand the statement "Not all knowledge requires evidence." The only difference is that the first statement is clearly false (if we know anything at all) while the second statement is very possibly true (I'll argue later it is clearly true).
Why this really matters (practically speaking)
It may be tempting for the defender of Dawkins to say "Who cares? You epistemologists are so nit-picky." But it really does matter. Here's one reason why. If (1) is false (indeed, necessarily false if we know anything), then some statements do not require evidence to be known. And this means that it is really important to begin to think which statements those might be. Otherwise you could end up dismissing legitimate knowledge claims for lacking evidence they do not require. And that would result in a critically impoverished epistemology.
To sum all this up, if you care about knowing what is true, you will not sweep a glaring infinite regress under the rug. Rather, you will reject (1) and accept that not all knowledge claims require evidence.