In order to advance to the city of the future we must have a force and a lever.  Man is the force, and the lever is the idea of Progress.  It is supplied by the study of history which displays the improvement of our faculties, the increase of our power over nature, the possibility of organising society more efficaciously.  But the force and the lever are not enough.  A fulcrum is also required, and this is to be found in the “solidarity” of the human race.  But this conception meant for Leroux something different from what is ordinarily meant by the phrase, a deeper and even mystical bond.  Human “solidarity” was a corollary from the pantheistic religion of the Saint-Simonians, but with Leroux, as with Fourier, it was derived from the more difficult doctrine of palingenesis.  We of this generation, he believed, are not merely the sons and descendants of past generations, we are the past generations themselves, which have come to birth again in us.

Through many pages of the two volumes [Footnote:  De l’humanite, 1840 (dedicated to Beranger).] in which he set forth his thesis, Leroux expended much useless learning in endeavouring to establish this doctrine, which, were it true, might be the central principle in a new religion of humanity, a transformed Pythagoreanism.  It is easy to understand the attractiveness of palingenesis to a believer in Progress:  for it would provide a solution of the anomaly that generations after generations are sacrificed for the sake of posterity, and so appear to have no value in themselves.  Believers in Progress, who are sensitive to the sufferings of mankind, past and present, need a stoical resolution to face this fact.  We saw how Herder refused to accept it.  A pantheistic faith, like that of the Saint-Simonian Church, may help some, it cannot do more, to a stoical acquiescence.  The palingenesis of Leroux or Fourier removes the radical injustice.  The men of each generation are sacrificed and suffer for the sake of their descendants, but as their descendants are themselves come to life again, they are really suffering in their own interests.  They will themselves reach the desirable state to which the slow, painful process of history is tending.

But palingenesis, notwithstanding all the ancient opinions and traditions that the researches of Leroux might muster, could carry little conviction to those who were ceasing to believe in the familiar doctrine of a future life detached from earth, and Madame Dudevant was his only distinguished convert.

5.

The ascendency of the idea of Progress among thoughtful people in France in the middle of the last century is illustrated by the work which Ernest Renan composed under the immediate impression of the events of 1848.  He desired to understand the significance of the current revolutionary doctrines, and was at once involved in speculation on the future of humanity.  This is the purport of l’avenir de la science. [Footnote:  L’Avenir de la science—­Pensees de (1848).  Published in 1890.]