Denying the Antecedent: A Common Fallacy?

Denying the Antecedent as a Legitimate Argumentative Strategy: A Dialectical Model

The standard account of denying the antecedent (DA) is that it is a deductively invalid form of argument, and that, in a conditional argument, to argue from the falsity of the antecedent to the falsity of the consequent is always fallacious. In this paper, we argue that DA is not always a fallacious argumentative strategy. Instead, there is a legitimate usage of DA according to which it is a de...

Human reasoning with imprecise probabilities: Modus ponens and denying the antecedent

The modus ponens (A → B, A ∴ B) is, along with modus tollens and the two logically not valid counterparts denying the antecedent (A → B,¬A ∴ ¬B) and affirming the consequent, the argument form that was most often investigated in the psychology of human reasoning. The present contribution reports the results of three experiments on the probabilistic versions of modus ponens and denying the antec...

On the interpretation of diagnostic tests: a common logical fallacy.

5%). Recoveries were similar when samples were sonicated before or after addition of perchloric acid. The compounds were determined in seven 250ML portions of a pooled whole-blood sample; the within-day CVs were 4.3% for 5-HT and 2.1% for TRP. Determinations made on 20-ML samples of pooled wholeblood (prepared by adding 10 ML of ascorbic and perchloric acid) gave CVs of 9.7% for 5-HT and 6.8% f...

The “banzhaf Fallacy” Fallacy

Denying the Liar Reaffirmed

In „Undeniably Paradoxical: Reply to Jacquette,‟ John Barker offers a criticism of my recent Polish Journal of Philosophy essay, „Denying the Liar.‟ If Barker is right, then I have correctly but unsurprisingly shown only that a construction other than the liar is not genuinely paradoxical, while leaving the liar paradox itself, properly so-called, completely untouched. Barker twice in the essay...