The leaps of knowledge in nineteenth-century science shook the foundations of religious and humanistic values throughout much of the world. The Darwinian Revolution and similar developments presented enormous philosophical challenges to Canadian scientists, philosophers, and men of letters. Their responses, many and varied, form a central theme in this collection of essays by one of Canada’s leading intellectual historians. McKillop explores the thought of a number of English-Canadian thinkers from the 1860s to the 1920s, decades that saw Canada's entry into the modern age. We meet Daniel Wilson, an educator and ethnologist for whom the pursuit of science was a form of poetic engagement, requiring the poet’s sensibilities; John Watson, one of the world’s leading exponents of objective idealism, whose philosophical premises helped to undermine the very religious tradition he sought to bolster; and William Dawson LeSueur, an apostle of Positivism, whose spirited defence of critical inquiry and evolutionary social ethics led him towards an entirely contradictory position. In addition to profiles of individuals, McKillop considers the ways in which their ideas operated in the context of Canadian institutions including the universities and the press. From these prospectives emerges a detailed analysis of the life of the mind of English Canada in an age of questioning, of doubt, and of struggle to reorient the intellectual and philosophical positions of a quickly changing society.