A powerful tradition in philosophy, of which Descartes is an influential proponent, holds that mind is something possessed by each individual human, independently of membership in a culture and society. But there is a dissenting tradition, which takes mental activities and states to be essentially social. In these Carus Lectures, Annette Baier looks at the relation between individual and shared reasoning, intending, and moral reflection. In each case she emphasizes the interdependence of minds and the role of social practices in setting the norms governing these activities. Professor Baier defends the view that our reasoning and our intention-formation require a commons of the mind - a background of shared reasonings, intentions, and actions. However, she concludes that moral reflection, as a social capacity, is still in its infancy, and that a commons of the mind is by no means assured with regard to morality.