2. The original text includes Greek characters. For this text version these letters have been replaced with transliterations. 3. The following misprints have been corrected: "predicability" corrected to "predictability" (page 33) "Aristole" corrected to "Aristotle" (page 313) 4. Other than the corrections listed above, printer's inconsistencies in spelling, punctuation, and hyphenation have been retained.