Category: Fallacies

The tu quoque fallacy is committed when it is assumed that because someone else has done a thing there is nothing wrong with doing it. This fallacy is classically committed by children who, when told off, respond with “So and so did it too”, with the implied conclusion that there is nothing wrong with doing […]

There are two types of claim: objective and subjective. Objective claims have the same truth-value for everyone. For example, the claim that the Earth is cuboid is an objective claim; it’s either true for everyone or false for everyone. It isn’t possible for the Earth to be cuboid for me, spherical for you, but flat […]

A sweeping generalization applies a general statement too broadly. If one takes a general rule, and applies it to a case to which, due to the specific features of the case, the rule does not apply, then one commits the sweeping generalization fallacy. This fallacy is the reverse of a hasty generalization, which infers a […]

Slippery slope arguments falsely assume that one thing must lead to another. They begin by suggesting that if we do one thing then that will lead to another, and before we know it we’ll be doing something that we don’t want to do. They conclude that we therefore shouldn’t do the first thing. The problem […]

The Latin phrase “post hoc ergo propter hoc” means, literally, “after this therefore because of this.” The post hoc fallacy is committed when it is assumed that because one thing occurred after another, it must have occurred as a result of it. Mere temporal succession, however, does not entail causal succession. Just because one thing […]

The no true scotsman fallacy is a way of reinterpreting evidence in order to prevent the refutation of one’s position. Proposed counter-examples to a theory are dismissed as irrelevant solely because they are counter-examples, but purportedly because they are not what the theory is about. Example The No True Scotsman fallacy involves discounting evidence that […]

A hasty generalisation draws a general rule from a single, perhaps atypical, case. It is the reverse of a sweeping generalisation. Example (1) My Christian / atheist neighbour is a real grouch. Therefore: (2) Christians / atheists are grouches. This argument takes an individual case of a Christian or atheist, and draws a general rule […]

The bifurcation fallacy is committed when a false dilemma is presented, i.e. when someone is asked to choose between two options when there is at least one other option available. Of course, arguments that restrict the options to more than two but less than there really are are similarly fallacious. Examples (1) Either a Creator […]

The cum hoc fallacy is committed when it is assumed that because two things occur together, they must be causally related. This, however, does not follow; correlation is possible without causation. This fallacy is closely related to the post hoc fallacy. Example As the graph below (taken from the Church of the Flying Spaghetti Monster […]

The complex question fallacy is committed when a question is asked (a) that rests on a questionable assumption, and (b) to which all answers appear to endorse that assumption. Examples “Have you stopped beating your wife?” This is a complex question because it presupposes that you used to beat your wife, a presupposition that either […]