[Sidenote: Philosophical peculiarities of the Age of Faith.] Philosophically, the most remarkable peculiarity is the employment of a false logic, a total misconception of the nature of evidence. It is illustrated by miracle-proofs, trial by battle, ordeal tests, and a universal belief in supernatural agency even for objectless purposes. On the principles of this logic, if the authenticity of a thing or the proof of a statement be required, it is supposed to be furnished by an astounding illustration of something else. If the character of a princess is assailed, she offers a champion; he proves victorious, and therefore she was not frail. [Sidenote: The character of its logic.] If a national assembly, after a long discussion, cannot decide "whether children should inherit the property of their father during the lifetime of their grandfather," an equal number of equal combatants is chosen for each side; they fight; the champions of the children prevail, and therefore the law is fixed in their favour. A relic of some martyr is bought at a great price; no one seeks to criticize the channel through which it has come, but every one asks, Can it work a miracle? A vast institution demands the implicit obedience of all men. It justifies its claim, not by the history of the past, but by promises and threats of the future. A decrepit crone is suspected of witchcraft. She is stripped naked and thrown into the nearest pond: if she sinks, she is innocent; if she swims, she is in commerce with the Devil. In all such cases the intrinsic peculiarity of the logic is obvious enough; it shows a complete misconception of the nature of evidence. [Sidenote: Its adoption of supernaturalism.] Yet this ratiocination governed Europe for a thousand years, giving birth to those marvellous and supernatural explanations of physical phenomena and events upon which we now look back with unfeigned surprise, half disbelieving that it was possible for our ancestors to have credited such things. [Sidenote: The Jews and Saracens destroy supernaturalism.] Against this preposterous logic the Mohammedans and Jews struck the first blows. We have already heard what Algazzali the Arabian says respecting the enchanter who would prove that three are more than ten by changing a stick into a serpent. The circumstances under which the Jewish physicians acted we shall consider presently.