Hermann Cohen, the founding father of Marburg neo-Kantianism, is known for criticising capitalism from a Kantian ethical perspective. Thus far, the role of the notion of humanity in this critique has been viewed as grounding what I shall call the ‘purposive labour reading’. This reading takes Cohen’s primary interest to lie in a reorganisation of work so that our humanity, which requires us to be treated as ends, remains intact. With the aim to better understand the relevant notion of humanity, I contextualise the discussion within the overall framework of Cohens’ neo-Kantian account of ethical cognition and situate his ideas in the context of his contemporary interlocutors. Revisiting Cohen’s remarks on socialism and capitalism against this backdrop reveals that his discussion of labour serves as an exemplar, showcasing how ethical rationality manifests in the liberal socialists’ demands. I argue that his primary aim was not to prepare the ground for a prescriptive labour theory – though this is likely to follow – but to argue for a framework alternative to historical materialism, allowing us to perceive and interpret social practices in an ethical light.