Tradition is to the group what memory is to the individual; and just as the sapping of memory may bring insanity, so a sudden break with tradition may plunge a whole nation into madness, like France in the Revolution.
The Durants considered their book to be about "The Age of Voltaire," but they perhaps missed one of the more interesting points to be made in this context: that Voltaire himself produced some texts in the radical Robespierre-Rousseau direction, and other texts in a more calmly reasonable Burke direction.