"In naming his book "Tertium Organum" Ouspensky reveals at a stroke that astounding audacity which characterizes his thought throughout-an audacity which we are accustomed to associate with the Russian mind in all its phases. Such a title says, in effect: "Here is a book which will reorganize all knowledge. The "Organon" of Aristotle formulated the laws under which the subject thinks; the "Novum Organum" of Bacon, the laws under which the object may be known; but "The Third Canon of Thought" existed before these two, and ignorance of its laws does not justify their violation. "Tertium Organum" shall guide and govern human thought henceforth."-From the Introduction.