This article presents an argument for veganism, using a formal-axiomatic approach: a list of twenty axioms are explicitly stated. These axioms are all necessary conditions to derive the conclusion that veganism is a moral duty. The presented argument is a minimalist or core argument for veganism, because it is as parsimonious as possible, using the weakest conditions, the narrowest definitions, the most reliable empirical facts and the minimal assumptions necessary to reach the conclusion. If someone does not accept the conclusion, (...) logical consistency requires that s/he should be able to point at axiom on which s/he disagrees. The argument exposes hidden assumptions and provides a framework for an overview of the philosophical literature on animal rights and vegetarianism / veganism. (shrink)