His opinion, and the general outlook that stands behind it, saddens me every time I hear it. It’s bad enough that it keeps folks from God. But it grieves my heart because this outlook is both widely accepted by unreflective people and patently absurd. It won’t withstand more than a moment’s reflection.

Behind this claim is an implicit epistemology¹ that I’ll call Folk Empiricism. It holds that:

For any statement P, P is reasonable to believe and proclaim only if P has been adequately tested with the five senses.

Folk Empiricism’s main idea is that we shouldn’t believe or assert what we cannot test (or have not tested) with our five senses. People who make claims like the one in the first paragraph are assuming it’s truth, whether they know it or not. But is Folk Empiricism an adequate test for the rationality of belief in God, or for the rationality of other every-day beliefs? More fundamentally, can it meet it’s own standards for rationality?

Recall my last article about self-defeating statements . There, I said that a statement is self-defeating when it exhibits the following three characteristics:

1. It establishes a standard of acceptability for an assertion.
2. It places itself under that standard of acceptability.
3. It fails to meet that standard of acceptability — i.e. it fails to meet the very standard of acceptability that it stipulates.

Since Folk Empiricism establishes that a statement is only reasonable to believe if it has been adequately tested by the five senses, and since Folk Empiricism is itself a statement, we must ask if it has been (or can be) adequately tested by the five senses. If it has not been (or cannot be), then Folk Empiricism is self-defeating.

To clarify what it means to test something with the five senses, consider the statement “there is an apple on the table.” To test this claim, all we have to do is look and see. If we see an apple on the table, then we can conclude that the claim is true; if see the table with no apple on it, we can conclude that it’s false. But how can we test Folk Empiricism with the five senses? What sight would confirm that we shouldn’t believe or assert what we can’t test with our five senses? What sound? Could a smell, taste or touch tell us that it is true? Obviously not. Because Folk Empiricism’s subject matter is not the sort of thing that can be seen, smelled, tasted, touched or heard, it can’t possibly be tested with the five senses. But this means that it fails to meet its own standard of acceptability, so Folk Empiricism is self-defeating.

Simply put, either it’s true or it’s not. If it is not, then it’s false. And since we obviously shouldn’t believe something that’s false, we obviously shouldn’t believe Folk Empiricism. If it is true, however, then it’s self-defeating so we still shouldn’t believe it. Either way, it’s a viewpoint in trouble. Not only are there no adequate reasons for believing Folk Empiricism, there can be no such reasons, for any adequate reason for believing it would demonstrate that it’s false! So much for Folk Empiricism as an adequate, reasonable guide for life decisions.

When put to the test, this way of analyzing the world fails to account for many of the things we actually know. Let me give some examples. (For brevity, I’ll use “seeing” as a synonym for “testing something with the five senses.” “I can see the effects of gravity” will mean the same thing as “I can test the effects of gravity with my five senses.”)

First, truth (i.e. correspondence with reality ) is not something we can see, so if we are limited to our five senses, we can have no grasp of it. If I believe that a book I ordered is at the bookstore, and then go to the bookstore and see the book, I know that my belief about the book was true. I can see the book there, but I cannot see my belief that the book was there, nor can I see the correspondence relationship between the books being there and my belief that it was there. In a case where my wife tells me I am angry and I’m not sure if she’s correct, I can introspect and decide the matter. If I take the thought “I am angry” and use it to search my inner feelings, when I experience my own anger, I come to know that my wife’s claim is true. But I cannot see my thought (“I am angry”), I cannot see the emotional state of anger itself and I cannot see the correspondence between the thought and my feeling of anger. Truth itself is not sense perceptible.

Second, knowledge is not something we can have reasonable views about if we are limited to our five senses. Consider the idea that knowledge is whatever our peers will let us believe.² On this view, all that’s required for me to know that the earth is flat (for instance) is that my peers allow me to say that it is. The whole point of defining knowledge is to determine what sorts of things we should and shouldn’t believe; but how in the world are we going to evaluate this definition if we are limited to what we can test with the five senses? With space-travel, the statement “the earth is flat” is testable by the five senses, and it is false. The statement “you should not proclaim something that’s false,” however, is not testable by the five senses, and neither is the statement “you should not proclaim that the earth is flat, even if your peers let you.” But in spite of the fact that we can’t smell, taste, touch, hear or see that we shouldn’t proclaim that the earth is flat, we obviously shouldn’t proclaim that it’s flat! These observations make evident (and making something evident is also not something we can recognize by our senses) how absurd Folk Empiricism is as a guide for knowledge.

We know a host of other things that are not testable by our five senses. It is not with the help of my five senses that I know my own states of consciousness (my thoughts, feelings, desires, beliefs, etc.), and I do not know my self with my five senses. When I have a sensation, I know that it is my sensation, but I cannot test this with my five senses: I can see a tree, but I cannot see or smell or hear that I am the one seeing the tree; I can smell a rose, but I cannot smell, hear or taste that I am the one smelling the rose. I don’t gain normative knowledge by testing things with my five senses either. I know what sorts of things I should and should not believe (rational normativity), what sorts of things I should and should not do (moral normativity) and what sorts of things I should and should not regard as beautiful (aesthetic normativity). But I can’t test any of these statements with my five senses. I should believe there are such things as birds, I should believe that kindness and honesty are virtues and I should believe that a sunset viewed from Maui over a turquoise ocean is beautiful. According to Folk Empiricsm, however, none of these beliefs are reasonable.

Even some things studied in the hard sciences cannot be known by the five senses. For example, we cannot see, touch, feel, hear or smell a magnetic field, but we know there are such things. We can see or feel the effects of such a field (for example, the iron filings falling into a particular pattern), but we cannot see the field itself. We infer that there must be such a field to explain the effects.

At the end of the day, Folk Empiricism is a wildly inadequate guide for living a rational life. There can be no good reason for believing it, and there are many good reasons for rejecting it. Objections to the reality of God based on Folk Empiricism (or an unconscious reliance on it) are, therefore, patently absurd. Seeing is not the same thing as believing, no matter how many times this mantra is chanted.

¹ An epistemology is a theory of knowledge. It is a doctrine that specifies what kinds of beliefs count as knowledge and how it is acquired. In general, a theory, idea or sentence is epistemological when it has to do with good vs. bad manners of believing, if it tells us what sorts of things we should believe and what sorts of things we should not believe.

² Richard Rorty’s position is often summarized this way.