Leon-Philip Schäfer

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.

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.

In metaethics, there is a close connection between ethical intuitionism and moral realism that is mostly based on the fact that intuitionism is capable of providing a solution to a philosophical problem, the problem of justification. This close connection, however, is more fragile than it may initially seem because the phenomenon of moral fallibility tends to estrange both views from each other: whereas moral realism is largely motivated by fallibilist presuppositions, ethical intuitionism is tacitly under suspicion of having infallibilist consequences. This charge of infallibilism is, to be sure, prima facie not surprising; nevertheless, its peculiar irony is rarely appreciated and shall, therefore, be analysed in the course of the paper.

In der transzendentalen Dialektik führt Kant die transzendentalen Ideen ein, deren systematischer Zusammenhang ambivalenter ist, als er zunächst erscheint. Das transzendentale Ideal, Kants Gottesbegriff, resultiert als eine der Ideen aus der Forderung der Vernunft, zu einem gegebenen Bedingten die vollständige Reihe der Bedingungen vorauszusetzen. Der ‚Grundsatz der durchgängigen Bestimmung‘ bildet Kant zufolge eine Variante dieses Prinzips. Außerdem beruht das Ideal, das hinsichtlich aller möglichen kontradiktorischen Prädikatenpaare bestimmt ist, auf seiner Grundlage. Entgegen Kants Darstellung wird gezeigt, dass dieser Begriff nicht durchgängig, sondern nur partiell bestimmt ist, da Kant in seinem Grundsatz Prädikate transzendental und nicht logisch entgegensetzen muss und sich die transzendentalen Gegensätze nur als eine Teilmenge der logischen offenbaren.

Die unvoreingenommene Suche nach der Wahrheit bildet nicht allein das Leitmotiv der Wissenschaft, sondern kann auch in der Ethik eine entsprechende Relevanz entfalten. Wer eine solche Auffassung näher beleuchten will, ist gut beraten, auf die Realismus-Debatten aus der modernen Philosophie zu rekurrieren und ihre oftmals vernachlässigten Verbindungen in den Blick zu nehmen. Das Buch leistet eine derartige Zusammenführung und macht den wissenschaftlichen und den moralischen Realismus in einem größeren Zusammenhang sichtbar, indem es deren wahrheitstheoretischen Grundgedanken herausarbeitet und sich gegen eine erkenntnistheoretische Überformung der Thematik wendet: Ein Realismus (über Wissenschaft oder Ethik) ist eine Auffassung über Wahrheit, nicht jedoch über unseren Erkenntniszugang zur Wahrheit. Im Zentrum eines Realismus steht die Vorstellung von der Objektivität der Wahrheit - eine Vorstellung, die für unser wissenschaftliches und ethisches Denken gleichermaßen von Bedeutung ist.

In his book The future of human nature, Jürgen Habermas argues against a scenario of liberal eugenics, in which parents are free to prenatally manipulate their children’s genetic constitution via germline interventions. In this paper, I draw attention to the fact that his species‐ethical line of argument is pervaded by a substantial ambiguity between an argument from actual intervention (AAI) and an argument from mere controllability (AMC). Whereas the first argument focuses on threats for the autonomy and equality of prenatally modified persons, the second argument takes all human beings, whether they have been modified or not, into account. Hence, when invoking Habermas in these debates, bioethicists need to consider carefully which argument they are referring to.

In this essay, I seek to clarify and defend a unified account of realism, i.e. a conception of realism that does not only apply to philosophy of science, but also acknowledges how realism is understood in other philosophical disciplines—particularly, how moral realism is treated in metaethics. I will argue that integrating scientific and moral realism is less straightforward than is commonly assumed, due to several substantial, but often unnoticed disanalogies that obtain between both views. As a consequence, scientific realists should consider modifying their traditional understanding and move towards an alternative conception of realism—one that is much more in line with the conception that moral realists usually adopt. Realism (about science or ethics) is, in the final analysis, best characterised as an alethic view which restricts itself to an idea about the objectivity of truth, rather than an epistemic view which underwrites more extensive theses concerning the accessibility of this truth for human knowledge.