As Nietzsche, who is so exclusively taken up by the psychological aspect, discards all accessories of scholarship, it is impossible to examine directly the accuracy of his assertions. The historical data will be found collected in Rée's paragraphs on resentment and the sense of justice, and in his section on the buying-off of revenge, i. e. settlement by fines.
Other thinkers besides Nietzsche (such as E. von Hartmann and Rée) have combated the view that the idea of justice has its origin in a state of resentment, and Nietzsche has scarcely brought to light any fresh and convincing proof; but what is characteristic of him as a writer is the excess of personal passion with which he attacks this view, obviously because it is connected with the reasoning of modern democracy.
In many a modern cry for justice there rings a note of plebeian spite and envy. Involuntarily many a modern savant of middle-class or lower middle-class origin has attributed an unwarrantable importance to the atavistic emotions prevalent among those who have been long oppressed: hatred and rancour, spite and thirst for revenge.
Nietzsche does not occupy himself for an instant with the state of things in which revenge does duty as the sole punitive justice; for the death feud is not a manifestation of the thrall's hatred of his master, but of ideas of honour among equals. He dwells exclusively on the contrast between a ruling caste and a caste of slaves, and shows a constantly recurring indignation with doctrines which have caused the progressive among his contemporaries to look with indulgence on the instincts of the populace and with suspicion or hostility on master spirits. His purely personal characteristic, however, the unphilosophical and temperamental in him, is revealed in the trait that, while he has nothing but scorn and contempt for the down-trodden class or race, for the slave morality resulting from its suppressed rancour, he positively revels in the ruling caste's delight in its power, in the atmosphere of healthiness, freedom, frankness and truthfulness in which it lives. Its acts of tyranny he defends or excuses. The image it creates for itself of the slave caste is to him far less falsified than that which the latter forms of the master caste.