We usually think of ethics as the province of religion and philosophy, not of science. Recently, however, a number of rather scientistically oriented authors have proposed that science — and in particular evolutionary biology, neurobiology, and psychology — is capable of answering moral questions, and that these disciplines will soon replace philosophy in this respect. I think the new scientism (and its close kin, the New Atheism) is mistaken, and yet there is indeed a sense in which scientific investigation is pertinent, even crucial, to the study of ethics. This approach was pioneered by the ancient Stoics, and captured in their motto, “live according to nature.” In order to be properly understood, however, this requires nothing less than a reconsideration of what we mean by “ethics,” “philosophy,” and “science.” In this talk I will re-introduce the Stoic approach and update it in the light of modern science, especially but not only biology. This New Stoicism may provide a path forward in overcoming the infamous divide between “the two cultures” identified and discussed by C.P. Snow back in 1959 on the occasion of his Rede Lecture. The sciences and the humanities can and ought to work together in the pursuit of a better future for humanity and the biosphere at large.