Friday, May 09, 2014

Argument from imagination

Other terms and/or related concepts

Appeal to ignorance; hidden premise; unfounded assumptions; Hume's razor; Ockham's razor; wishful thinking; conspiracy thinking; magical thinking; intuition; simpleminded certitude.


The advocate forwards a hypothesis and assumes it is true without any evidence other than their imagination. They do not refer to any external or empirical evidence in support of their claim. They rely solely on intuition, making unequivocal statements about their hypothesis as if it is a fact, when in reality it is something based on an unfounded belief or their imaginings.


1. Jan Jones is deputy principal as a large primary school. She is reviewing a colleague's Year 3 mathematics assessment, which asks students to photograph and classify 3-dimensional objects. She says: "I don't think Year 3s would find his investigation interesting. I'd imagine they're more interested in doing something hands-on with concrete materials rather than this."

2. A recent government inquiry recommended that health funds stop covering homoeopathy on the grounds it is pseudoscientific, has no plausibility or demonstrable efficacy beyond placebo. Johnson Royale, spokesperson for the Homoeopathic Society, is attempting to defend homoeopathy on a talk show.

One of the hosts asks a surprisingly adroit question: "How could homoeopathy have any effect given there is no trace of the supposed active ingredient after it has been diluted hundreds or thousands of times? And then how is it that the other natural trace elements in the water have no effect given the exact same thing happens to them?"

Johnson says: "We're still not sure. The leading views are that water has a memory, which could be something to do with quantum theory or information theory. And water remembers the ingredient we want because we shake it 10 times in a special way every time we dilute it."


An argument from imagination can be thought of as the opposite of an appeal to ignorance (something cannot be true because the advocate cannot imagine how it could be true); that is, an advocate states their position is true because they imagine it to be true. They will rarely phrase it this way, but if we consider the two examples above, neither cites any external evidence in support of their claims. They assert a belief and justify it with another belief.

In the first example, Jan makes a seemingly plausible statement. It is reasonable to think students in Year 3 will find hands on activities interesting. However, this does not mean they will find the proposed assessment uninteresting. More importantly, she does not have any evidence for her position other than what she imagines to be the case. She is in her mid-fifties. What she imagines 8 year olds find interesting or uninteresting might not be as accurate as she thinks. Given this, it would be worth trialling the assessment to gather some empirical evidence, rather than throwing it out based on her intuition.

The second example, homoeopathy, contradicts all the known laws of physics and chemistry. Any possible explanation about how homoeopathy works is stated as if one of them is actually true. Again, they provide no external evidence or coherent theory. We are expected to believe the supposed mechanisms imagined by the proponents. In this case, we would also be contradicting well-established physics and chemistry. The imaginings of how homoeopathy supposedly works do not pass the test of coherence with the rest of science. Either what Johnson proposes is wrong, or if right, the laws of physics and chemistry need to be re-written. In order to do this we will need evidence on the level of Hume's razor. Other elements of homoeopathy, such as the dilution process known as "succussion", enter the realm of magical thinking.

Imagination is essential. Scientific discovery and technological progress all involve creativity and imagination. The clichéd robotic and unimaginative scientist would never discover anything. The issue arises when one is too simpleminded to recognise the difference between imaginings, and scientific theory and evidence; or too lazy or incapable of doing the work to investigate and test what they imagine.

A simple way to approach arguments from imagination is to point it out bluntly. If a proponent claims: "Doing X will cause y", responded to by rephrasing: "In your imagination, doing X will cause y." Try not to be too mocking. Just point out that all you are asking for is some evidence beyond the proponent's own opinion.