Félix Ravaisson's is one of the most influential and pivotal texts of modern French thought. Commissioned by the Minister of Public Instruction as one of a series of reports to record the progress of the French sciences and humanities for Paris' second world fair, the 1867 , it was published with the others the following year. In the report Ravaisson argues, with verve and generosity, and with an unparalleled command of the century's intellectual developments, that the myriad voices in nineteenth-century French thinking were beginning to form a chorus, one that was advancing towards a new, more concrete form of spiritualist philosophy able to resist materialist, mechanist and sensualist doctrines while incorporating recent developments in the life-sciences. As Henri Bergson noted, it effected a "profound change of orientation in university philosophy" and for decades afterwards students learnt its concluding sections by heart in order to pass public examinations. Bergson's own , which made him the world's most celebrated living philosopher at the end of the long nineteenth century, is, with its psychological interpretation of biological evolution, a direct expression of the new philosophical orientation that Ravaisson had divined in the report.