- 1839-1846: an early exploratory period, marked by early insights and some provocative statements, but also by inconsistent or non-existent definitions of key terms (“possession,” for example;)
- 1848-1852: a period when much of Proudhon’s focus was on the 1848 Revolution and its aftermath in the Second Republic, marked by more occasional writings, many of them related to political events and rivals, and also marked by some rather dramatic variations in the strong claims Proudhon was willing to make at any given moment; and
- 1853-1865: a mature period, beginning with The Philosophy of Progress and the clarification of Proudhon’s project that took place in that work, marked by a much more consistent approach to keywords (property, etc.) and the development of an increasingly complex, consistent, and powerful social science.
There’s no point in leaning too heavily on this scheme, since there is a considerable amount of useful work in every period of Proudhon’s career, but as a matter of emphasis, it may help to recognize that the work in the period of the Second Republic may not be Proudhon’s most consistent or least distracted—however interesting that period, and Proudhon’s responses to it, may be in other terms.