In this paper, I show how a concept of ethics can be derived from Hannah Arendt’s theory of action in The Human Condition, which contains from her call for action. When she looks at the ‘political actor’, as well as at the concept of ‘political situation’, her ethical claim is first of all the need to take initiative, to act. Hence, ‘political situations’ as she defines them are discussed as common responsibilities. But common responsibility is rooted in the in-between of human beings, rather than in individual human nature and is determined by Arendt’s principle of humanity. Therefore, at the centre of an implicit Arendtian ethics stands the world and the in-between of human beings.