Utilitarian thinkers focused not on spiritual development but on the ascent towards a perfectly ordered society in which all could lead a comfortable life. The emergence of more complex societies in the course of history was used by thinkers such as Condorcet to justify the hope of achieving such a society in the future. Opinions differed on the best way to approach the goal. British social theorists followed a model in which free-enterprise individualism gradually threw off the imperfections of less-mature forms of social order. In France, Comte's positivism saw rational planning by experts as the way forward, a position adopted by social planners into the twentieth century. The Marxists, meanwhile, modified Hegel's system of developmental stages to give a more radical vision in which revolution was the only way of achieving the final goal. All of these social thinkers accepted a significant role for technological innovation as a means of improving the human condition, but tended to see industrial development as following a predetermined path.