Although the economic thought of Marshall and Pigou was united by ethical positions broadly considered utilitarian, differences in their intellectual milieu led to degrees of difference between their respective philosophical visions. This change in milieu includes the influence of the little understood period of transition from the early idealist period in Great Britain, which provided the context to Marshall’s intellectual formation, and the late British Idealist period, which provided the context to Pigou’s intellectual formation. During this latter period, the pervading (...) Hegelianism and influences of naturalism arising from the ideas of Charles Darwin and Herbert Spencer were challenged by Hermann Lotze, a key transitional thinker influencing the Neo-Kantian movement, who recognised significant limits of naturalism, on the one hand, and the metaphysical tenor of absolute idealism, on the other, and attempted to provide a balance between the two. The goal of this paper is to make the provisional case for the argument that Pigou’s views on ethics were not only directly influenced by utilitarian thinkers like Mill and Sidgwick, but they were also indirectly influenced by Hermann Lotze, via the influence of the Neo- Kantian movement on late British idealism. To that end, Pigou’s essays in The Trouble with Theism (1908), including his sympathetic consideration of the ethics of Friedrich Nietzsche, reflect the influence of Lotze indirectly through the impact at Cambridge of: James Ward’s critique of associationist psychology, and consideration of the limits of naturalism including the critique of evolutionary ethics; Bertrand Russell’s rejection of neo-Hegelianism and, together with Alfred North Whitehead, the development of Logicism; and G.E. Moore’s critique of utilitarian ethics on the basis of the naturalistic fallacy and the development of his own intuitionist system of ethics. (shrink)