(2) Cruelty, which means the maximum deficiency in Compassion, is the mark of the deepest moral depravity. Therefore the real moral incentive must be Compassion.
(3) Compassion is the only thoroughly effective spring of moral conduct.
(4) Limitless Compassion for all living things is the surest and most certain token of a really good man.
(5) The evidence of separate matters of detail.
(6) Compassion is more easily discerned in its higher power; it is more obviously the root of loving-kindness than of justice.
(7) Compassion does not stop short with men; it includes all living beings.
(8) Considered simply from the empirical point of view, Compassion is the best possible antidote to Egoism, no less than the most soothing balsam for the world's inevitable suffering.
(9) Rousseau's testimony is quoted, as well as passages from the Paṅća-tantra, Pausanias, Lucian, Stobaeus, and Lessing; and reference is made to Chinese Ethics and Hindu customs.
Part III. closes (Chapter IX.) with an inquiry into the Ethical Difference of Character. The theory that this difference is innate and immutable is supported by numerous extracts from various writers of all periods, and illustrated in many ways. But all the evidence accumulated hardly amounts to more than so many hints and indications, and the matter (says Schopenhauer) was only satisfactorily explained by Kant's doctrine of the Intelligible and Empirical Character. (Cf. Part II., Chapter VIII.) According to this, the ethical difference between man and man is an original and ultimate datum, caused by the transcendentally free act of the Intelligible Character, that is, the Will, as Thing in itself, outside phaenomena; the Empirical Character being, so to say, the reflection of the Intelligible, mirrored through the functions of our perceptive faculty, namely, Time, Space, and Causality. Hence the former, while manifested in plurality and difference of acts, yet necessarily always wears the same unchangeable features, inasmuch as it is but the appearance-form of the unity behind. If the reader asks why "the essential constitution of the Thing in itself underlying the phaenomenon" is so enormously different in different individuals, it can only be said that our intellect, conditioned, as it is, by the laws of Causality, Space, and Time, has no power to deal with noumena, its range being limited to phaenomena; and that therefore this question is one of those which have no conceivable answer. (Cf. Die Welt als Wille und Vorstellung, vol. ii., chap. 50., Epiphilosophie.)[7]