In the fourth Part of the treatise Schopenhauer attempts the metaphysical explanation of Compassion, which for those, who still think that Metaphysics is something more than a pseudo-science of the past--like Alchemy or Astrology--will have special interest. It should be observed (as is pointed out in our author's Preface to the first edition) that the line of thought followed does not belong to any particular metaphysical school, but to many; being in fact a principle at the root of the oldest systems in the world, and traceable in one form or another down to Kant. As in the dawn of history it was our own Aryan forefathers, who divined with subtle intuition the ideality of Time and Space; so in the fulness of the ages it was reserved for another Aryan of Scotch descent to formulate the same in exact language. Now, by the vast majority of men the ideality of the _principium individuationis_ is undoubtedly either not consciously realised at all, or else but dimly perceived under the form of allegories and mythologies. Yet, if this theory be true, if individuation be only a phaenomenon depending on the subjectivity of Time and Space, then Compassion, and its external expression, the _ἀγάπη_ that is greater than Faith and Hope, receive their final explanation. And every _εὐθανασία_; every word that vibrates in harmony with the inspired rhapsody of 1 Corinthians xiii.; every act of genuine justice, or of true loving-kindness, done by man to man, as well as the uplifting emotion which stirs our hearts at the sight of such conduct:--all these things become fraught with a new and luminous significance: the secret writing is interpreted, its deepest meaning disclosed.