The objective of this paper is to recall the forgotten opposition of Clément Juglar to the colonization of Algeria, the originality of this position, and his contributions to the genesis of analysing colonial institutions. Juglar was not a theoretician of colonialism, but a liberal economist who rejected the process of colonization on economic grounds. This paper provides evidence that conventional wisdom on French colonialism is indebted to his work. The issues of capital returns in the colonies, French colonialism as mercantilism and protectionism, and the role of colonial institutions in economic development were all addressed by Juglar. He identified property rights and colonial institutions as central issues in his explanation of the predictable failure of colonialism, and in doing so he can be regarded as a forerunner of neo-institutionalist analysis of colonialism.