The ‘Arbitrariness’ of Ethics: Pursuing Wittgenstein’s Suggested Analogy to Logic and Mathematics

Wittgenstein wrote relatively little on ethics, and his remarks on the subject are often sparse and conceptually dense. As a result, scholarship on his (meta)ethical thought faces challenges of continuity and interpretation. One of the most detailed glimpses into his later ethical thinking comes from Rush Rhees’s notes, particularly a conversation dated September 12, 1945.

In this discussion, Wittgenstein reiterated his rejection of ethical enquiry as a search for “the essential nature of goodness or duty” or “the right ethics,” viewing these as misguided pursuits of moral philosophy. Yet he also maintained that rejecting this picture need not entail abandoning the idea of a moral imperative—raising important questions about how these views might coexist.

Although he did not address this tension explicitly, Wittgenstein suggested that the “arbitrariness” of adopting ethical systems could be analogized to the “arbitrariness” involved in adopting mathematical or grammatical systems. This paper explores that analogy by reconstructing what Wittgenstein may have understood as the arbitrariness of ethics. The account draws on his extensive writings on mathematics and logic—including The Big Typescript and later lectures—as well as Rhees’s transcriptions of their conversations. The paper concludes by examining how, for Wittgenstein, ethics like mathematics also involves a non-arbitrary dimension rooted in human agency and commitment.Vincke, Vincent. “The ‘Arbitrariness’ of Ethics: Pursuing Wittgenstein’s Suggested Analogy to Logic
and Mathematics.” In Feminist Philosophy — Language, Knowledge, and Politics, edited by Isabel G.
Gamero, Amadeusz Just, and Jasmin Trächtler, in cooperation with Joseph Wang-Kathrein, Beiträge
der Österreichischen Ludwig Wittgenstein Gesellschaft – Contributions of the Austrian Ludwig
Wittgenstein Society, vol. XXXI, Kirchberg am Wechsel: Österreichische Ludwig Wittgenstein
Gesellschaft, 2025.