argumentum ad ignorantiam

The "argument from [or to] ignorance" is a logical fallacy. Here's what one entry says about it:

The argument to ignorance is a logical fallacy of irrelevance occurring when one claims that something is true only because it hasn't been proved false, or that something is false only because it has not been proved true. A claim's truth or falsity depends upon supporting or refuting evidence to the claim, not the lack of support for a contrary or contradictory claim. (Contrary claims can't both be true but both can be false, unlike contradictory claims. "Jones was in Chicago at the time of the robbery" and "Jones was in Miami at the time of the robbery" are contrary claims--assuming there is no equivocation with 'Jones' or 'robbery'. "Jones was in Chicago at the time of the robbery" and "Jones was not in Chicago at the time of the robbery" are contradictory. A claim is proved true if its contradictory is proved false, and vice-versa.)

The fact that it cannot be proved that the universe is not designed by an Intelligent Creator does not prove that it is. Nor does the fact that it cannot be proved that the universe is designed by an Intelligent Creator prove that it isn't.

The argument to ignorance seems to be more seductive when it can play upon wishful thinking. People who want to believe in immortality, for example, may be more prone to think that the lack of proof to the contrary of their desired belief is somehow relevant to supporting it.

Arguing that the materialist case is flawed is not support for the substance dualist's side, which does seem to include a bit of wishful thinking. The hidden agenda of most substance dualists seems to be along the lines of, "People have souls." We'd all love to believe that we don't disappear at death. The substance dualist makes the mistake of arguing from ignorance when trying to put forth his own claim that mind is immaterial-- this in blatant disregard of (but demonstrating an amazing flair for wildly reinterpreting) evidence pointing to the intimate association between the brain/body suite and one's mental activity. The canard that makes me laugh the most: There is no evidence of a causal connection between material and mental states.

Let's suppose the mind is immaterial. Let's grant that qualia are in the mind. A problem arises: qualia are components of experience, but we live in a material world that impinges on our senses and provides us the grist for our qualia. What if there were no material world? Would a person have qualia?

Every example of qualia has invoked the physical world: the taste of juice, the feel of the wind, the sound of a symphony, the sight of a work of art. I tend to think this implies a tight linkage between qualia and the physical world, but I suspect that substance dualists, wanting to preserve the mind's separateness from matter, would be at pains to deny this. On what grounds would they do so? What qualia would there be without material reality? Note that the dualists' denials rely on material motor neurons to type themselves out onto keyboards; they rely on material keyboards, computers, and the Internet, and further rely on material people, material eyes trained on material monitors, to read the denials. How seriously can such denials be taken?


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