From Part 1: There are many discussions on agnostic.com where one member demands proof to substantiate the claims made in another’s comment. Members often have wildly different interpretations of what constitutes proof, what constitutes supporting evidence, and even philosophically how we positively know something. Parts 1 & 2 can be linked here: "What constitutes evidence? proof? Part 2" In this installment, we look at “proving the negative” or invalidating a generally accepted claim.

A proof that two concepts are not causally linked can be rather easy in many cases. If an individual simply gives a couple of counter examples, then the original claim of causation is weakened. If the number of counter examples is a reasonable fraction of the known cases, then the original assertion is invalid. (Alternatively, there must be at least another factor at play to produce a large number of anomalies.) It is not necessary for the person providing the counter examples to provide reference to any external authority, Google search, or webpage.

If the advocate against the causally linked concepts can’t identify a counter example, his/her challenge is much tougher but not impossible. The AA (against advocate) might start by pointing out critical factors that are missing from the original conclusions that led to the presumed connection. S/he might point out logical inconsistencies internal to the original arguements. Here the AA has to be very careful not to cheat. See the attached Methods of Argument Cheating. Also, be aware of “The Fallacy of Reasons.” Fallacy: the conclusion can be dismissed simply because the advocate can give no reasons (or apparently only poor reasons) to support the conclusions. S/he might be right, but has not yet worked out how to articulate the complex, systems-literate approach to make it sufficiently clear and robust to survive objections.

Have happy, safely-clean, and lively discussions on agnostic.com using vigorously appropriate arguments.