Meliorism is an idea in metaphysical thinking holding that progress is a real concept leading to an improvement of the world. It holds that humans can, through their interference with processes that would otherwise be natural, produce an outcome which is an improvement over the aforementioned natural one.
Meliorism has also been used by Arthur Caplan to describe positions in bioethics that are in favor of ameliorating conditions which cause suffering, even if the conditions have long existed (e.g. being in favor of cures for common diseases, being in favor of serious anti-aging therapies as they are developed).
Condorcet's statement, "Such is the object of the work I have undertaken; the result of which will be to show, from reasoning and from facts, that no bounds have been fixed to the improvement of the human faculties; that the perfectibility of man is absolutely indefinite; that the progress of this perfectibility, henceforth above the controul of every power that would impede it, has no other limit than the duration of the globe upon which nature has placed us." anticipates James' meliorism.
Rousseau's treatment is somewhat weaker.
- Shaver, S. (July 1996). T. Eardly, ed. "Liberalism, gender and social policy" (PDF). Social Policy Research Centre.
- Marie-Jean-Antoine-Nicolas Caritat, Marquis de Condorcet, "Outlines of an historical view of the progress of the human mind" 
- Rousseau, J. J., (1754). "Discourse on the Origin of Inequality"(Translated by G. D. H. Cole)