McLuhan drew from many, many sources in order to develop these ideas; the work of Canadian political economist and media theorist Harold Innis was instrumental for him. Innis's technique, like McLuhan's, forswears the building up of a convincing argument, or any attempt at "proof," instead gathering in a ton of disparate ideas from different disciplines that might seem irreconcilable at first; yet considering them together results in a shifted perspective, and a cascade of new insights.