Ad hominem arguments in scientific discourses – rational heuristic or dangerous immunisation strategy?

Abstract Ad hominem arguments have, in terms of their relevance for scientific discourses, a peculiar status that seems to be surprisingly unfathomed in modern philosophy of science. The main aim of the current paper is to shed some light on this latent blind spot and to familiarise philosophers of science with some of the recent discussions that this topic has launched in argumentation theory. In particular, I would like to examine whether ad hominem arguments are to be regarded as epistemically detrimental and should be kept out of scientific discussions altogether or whether we should embrace a more nuanced evaluation that allows for the view that such arguments can be legitimate sometimes. While the modern literature in argumentation theory tends to support a remarkably permissive assessment of ad hominem arguments, the paper advocates for a more cautious conclusion: it shows that ad hominem arguments have the potential to damage or even outright destroy the basis of rational discussions, by substituting the factual criticism of theories with the personal denunciation of their creators. Because of this, a careless rehabilitation of such arguments is not recommended.