In examining developments in Ontario's law of employers' liability during the latter half of the nineteenth century, Professor Tucker notes the striking changes - in doctrine, style of reasoning and judicial attitude - toward compensation for injured workers that came about following legislative modification of the common law in this area in 1886. He then discusses a number of theoretical frameworks that might explain the changes in legal response to industrial capitalism in that period, and finds that they do not adequately account for the observed changes. Finally, he develops the outline of a theory of the relative autonomy of the law from a Marxist perspective which, in his view, provides a better foundation for understanding the dynamics of legal change than do the other theories reviewed in the article.