Notwithstanding all its progress, philosophy has been unable as yet to offer the masses any ideal that can charm them; but, as they must have their illusions at all cost, they turn instinctively, as the insect seeks the light, to the rhetoricians who accord them what they want. Not truth, but error has always been the chief factor in the evolution of nations, and the reason why socialism is so powerful to-day is that it constitutes the last illusion that is still vital. In spite of all scientific demonstrations it continues on the increase. Its principal strength lies in the fact that it is championed by minds sufficiently ignorant of things as they are in reality to venture boldly to promise mankind happiness. The social illusion reigns to-day upon all the heaped-up ruins of the past, and to it belongs the future. The masses have never thirsted after truth. They turn aside from evidence that is not to their taste, preferring to deify error, if error seduce them. Whoever can supply them with illusions is easily their master; whoever attempts to destroy their illusions is always their victim. 3. EXPERIENCE Experience constitutes almost the only effective process by which a truth may be solidly established in the mind of the masses, and illusions grown too dangerous be destroyed. To this end, however, it is necessary that the experience should take place on a very large scale, and be very frequently repeated. The experiences undergone by one generation are useless, as a rule, for the generation that follows, which is the reason why historical facts, cited with a view to demonstration, serve no purpose. Their only utility is to prove to what an extent experiences need to be repeated from age to age to exert any influence, or to be successful in merely shaking an erroneous opinion when it is solidly implanted in the mind of the masses. Our century and that which preceded it will doubtless be alluded to by historians as an era of curious experiments, which in no other age have been tried in such number.