The defamatory potential of ad hominem criticism: guidance for advocacy in public forums

Abstract

Ad hominem criticism seeks to discredit an argument by attacking the qualities of the arguer, rather than the merits of the argument. Although there are compelling reasons to avoid ad hominem criticism, it may sometimes be appropriate as a means of responding to ‘expert’ arguments advanced in public forums. However, conservation biologists should evaluate the defamatory potential of any proposed ad hominem criticism and consider whether the criticism: (1) impugns a person’s reputation in a trade, profession or business; (2) has a factual grounding that is based on evidence that could be used in court; and (3) is better formulated as a statement of opinion than as a statement of fact. From a defamation perspective, the purpose and context for an ad hominem criticism is critical and conservation biologists should always consider whether, if viewed objectively, their conduct in making the criticism would be assessed as fair-minded, reasonable, and supportive of debate over an issue of public interest. Isolated and unsupported ad hominem remarks should not be made. Conservation biologists should also be aware that there are circumstances in which critiques of the methods, analyses, logical approaches, and conclusions of an expert could be said to be defamatory of that person, but that courts also recognise the importance of scientific debate. Conservation biologists should carefully consider the wording of any proposed ad hominem criticism, particularly in terms of the precise facts to be alleged and the particular evaluative words or phrases to be applied, and should also ensure that the criticism has a proper purpose, is well supported, and clearly distinguishes between comments that express an opinion and those that state a fact.