Liberal internationalism remains the dominant perspective of those who study Canadian foreign policy, many of whom evoke the "Golden Age" of Canadian diplomacy under Lester B. Pearson. This article analyses Pearson's own ideas about the approach that Canada should take on the world stage and reveals recurring themes in his thinking. Analysis of these ideas imparts some general guidelines for conducting Canadian foreign policy. Primary documentary material in the Public Archives of Canada, interviews with Pearson's son and colleagues as well as Pearson's own writing are used to interpret the central elements of his belief system and assess his contribution to liberal internationalism. This article increases understanding of the effect of belief systems on foreign policy-making and of the impact of the liberal ideology that permeated North American culture during Pearson's era.