Continued from Part 1
4. Some Examples: Tooth Fairies, Leprechauns, Santa Claus, Teapots, and Invisible Objects
Let me see if I can put all this together to answer your question with some examples which are thought to pose a problem for the line of thought defended thus far. Your question basically was when absence of evidence counts as evidence of absence. Answering this will depend upon whether our epistemic situation satisfies the Evidence Expectation and Knowledge Expectation Criteria for the object in question: Should one expect to possess evidence sufficient to know that object O exists? If a rhino were in the room, then the answer is “Yes.” Thus, looking about and seeing no rhino, that itself is evidence there is none present.
But what about things like the Tooth Fairy, leprechauns, and Santa Claus? Atheists claim they don’t need to disprove God for the same reason they don’t need to disprove the existence of Tooth Fairies, leprechauns, and Santa Claus. The problem with the comparison with the last two items is that, while our epistemic situation regarding God doesn’t always satisfy the Evidence Expectation and Knowledge Expectation Criteria, our epistemic situation regarding leprechauns and Santa Claus does — we can, and do, disprove them all the time; it’s just that there are few, if any, people arguing for their existence so we’re never called upon to give those reasons. If Santa existed we should expect to see, but don’t, lots of evidence of that fact, including warehouses at the North Pole, a large sleigh, and so forth; similarly, were there biologically tiny human beings on this planet we should expect to see, but don’t, their evidence: miniature villages, waste products, the bones of their deceased — evidence similar to what we have for mice, hamsters and other small critters. If there were more people today who made a case for leprechauns and Santa Claus then it would be entirely appropriate for us to enter into dialogue with them, giving reasons for their non-existence.
At this point an atheist might object that the Tooth Fairy is different from leprechauns and Santa Claus because she’s invisible. (Is she invisible in the story?) Suppose she is invisible. According to the tale she collects teeth left under children’s pillows leaving behind a reward (usually money). Evidence we should expect to see if she existed then would be money left behind, stolen teeth, etc. Do we find such evidence? Well, no we don’t, but we would expect to if she existed. So, even the Tooth Fairy satisfies the Evidence Expectation and Knowledge Expectation Criteria. So because we lack evidence of her, we say she doesn’t exist (sorry kids!).
Suppose the atheist agrees that the reason why we deny Tooth Fairies, leprechauns and Santa Claus is because we do have evidence for their absence. He might nonetheless insist that the situation is significantly different for other objects which are causally isolated from us. A case in point is Russell’s famous teapot which circles about the sun, an object which is (for the most part) causally isolated from us. Do we need to be agnostic about it? Can we say it doesn’t exist? I think we know it doesn’t exist because it wasn’t put there by the Russian or American astronauts; and we know that matter in the universe does not self-organize into teapot shapes. So really, we have a great deal of evidence that Russell’s teacup doesn’t exist; and since our discussion is confined to cases where we infer the non-existence of something simply on the basis of absence of evidence for it, the example is irrelevant.
Another Objection and a Reply
But now imagine the atheist objecting:
OK, very well, I grant everything you say thus far about Santa Claus, and all the rest; but we don’t have to abide by your Criteria when it comes to objects which are both invisible (like the Tooth Fairy) and causally undetectable (like the teapot). For example, an invisible floating, pink elephant over my head. There’s no such thing.
The theist could reply:
Your example is charming and rhetorically clever but incoherent. Can something that is invisible even be an elephant? If so, then it surely isn't very much like a normal elephant— a massive, material object which exhibits all sorts of physical properties. Your “invisible elephant” question is really just a rhetorically clever sleight of hand; the question doesn’t make much sense in the first place and perhaps should be rephrased as something like: "Do we know there are not immaterial things around us?" to which the answer should be "No" in either of two senses: (i) No, because we have no evidence that there are not immaterial things, or (ii) No, because there are immaterial things around us, e.g. God, angels, immaterial minds, qualia, abstract objects like numbers or propositions, etc.9