This conceptual paper starts from the hypothesis that moral reflection is not a part of Lean Thinking. In an era where corporations are supposed to pay attention to the consequences of their actions (e.g. the Corporate Sustainability Reporting Directive), this may cause a mismatch between the Lean body of knowledge and the expectations society has from the corporate world. Can ethics provide tools to adapt Lean Thinking to the complex demands of current society? This paper explores a way by means of an experiment where a certain ethical approach is followed in order to find something that may be called a ‘moral true north’. The key issue in this paper is a) that morality is not an explicit part of Lean Thinking, and b) that, in order to bridge the gap between Lean Thinking and ethics, Lean practitioners have to step outside the field of Lean Thinking into the field of ethics for a moment. This paper does such a thing with one example, the responsibility ethics of Hans Jonas (published in 1979), in which he argues that mankind ought to strive for a sustainable future, without taking anything for granted.