I. Philosophic embassy from Athens to Rome, 120—Lectures of Carneades on Justice _versus_ Expediency, 121—Public and private morality in Rome: position of Cato, 122—His motion for the dismissal of the embassy, 123—Carneades and Plato, 123. II. Different meanings of the word scepticism, 123—False scepticism as an ally of orthodoxy, 125—Vein of doubt running through Greek mythology, 126—Want of seriousness in Homer’s religion, 127—Incredulous spirit shown by some of his characters, 127—Similar tendency in Aeschylus and Herodotus, 128—Negative and sceptical elements in early Greek thought, 128. III. Protagoras the true father of philosophical scepticism, 129—The three theses of Gorgias, 130—Sceptical idealism of the Cyrenaic school, 132—Scepticism as an ally of religion with Socrates and Plato, 133—The _Parmenides_, the _Sophist_, and the _Timaeus_, 134—Synthesis of affirmation and negation in metaphysics and in dialectics, 135—Use of scepticism as a moral sanction by the Megarians, 136. IV. Life and opinions of Pyrrho, 137—Denial of first principles: present aspect of the question, 139—Practical teaching of Pyrrho, 140—Encouragement given to scepticism by the concentration of thought on human interests, 141—Illogical compromise of Epicurus, 143—Parasitic character of the sceptical school, 143. V. Origin of the New Academy, 144—Character and position of Arcesilaus, 145—The Stoic theory of certainty, 146—Criticism of Arcesilaus: his method of infinitesimal transitions, 147—Systematic development and application of the Academic principle by Carneades, 148—His analysis of experience, 149—His attack on syllogistic and inductive reasoning, 150—His criticism of the Stoic and Epicurean theologies, 151—Sceptical conformity to the established religion, 153—Theory of probable evidence as a guide to action, 154—_A priori_ reasoning of the ancient sceptics, 155—Their resemblance in this respect to modern agnostics, 156—and also in their treatment of ethics, 157—Obedience to Nature inculcated by Carneades, 158. VI. Return of Greek thought to the Sophistic standpoint, 158—Obstacles to a revival of spiritualism, 159—Platonising eclecticism of the Academy: Philo and Antiochus, 160—Approximation of Stoicism to Aristotle’s teaching, 162—General craving for certainty and stability in philosophy, 163. VII. Sudden paralysis of the Greek intellect, 165—Probable influence of the new Latin literature, 165—Adaptation of Greek philosophy to Roman requirements, 166—Increased prominence given to the anti-religious side of Epicureanism, 167—Its ethics ill-suited to the Roman character, 168—Growing popularity of Stoicism: Panaetius and Posidonius, 168—It is temporarily checked by the influence of the Academy, 169.