The ablest part of the lectures of Archer Butler of Dublin, is devoted to the Platonic philosophy. It is a criticism and an eulogium. No modern writer has written more enthusiastically of what he considers the crowning excellence of the Greek philosophy. The dialectics of Plato, his ideal theory, his physics, his psychology, and his ethics, are most ably discussed, and in the spirit of a loving and eloquent disciple. He represents the philosophy which he so much admires as a contemplation of, and the tendency to, the absolute and eternal good. The good is enthroned by Plato in majesty supreme at the summit of the whole universe, and the sensible world is regarded as a development of supreme perfection in an inferior and transitory form. Nor are ideas abstractions, as some suppose, but archetypal conceptions of the divine mind itself--the eternal laws and reasons of things. The sensible world is regarded as an imperfect image of ideal perfection, yet the uncertainty of physical researches is candidly admitted. The discovery of theological and moral truth, is the great object even of the "_Timoeus_." Hence the physics of Plato have a theological character--are mathematical rather than experimental. The psychology represents the body as the prison of the soul, somewhat after the spirit of oriental theogonists, and the aim of virtue is to preserve the distinctness of both, and realize liberty in bonds. The doctrine of preexistence is maintained, as well as a future state. In the ethics, the perfection of the human soul--the perfection which it may attain--is distinctly unfolded, and also the unity of the great ideas of the beautiful, just, and good. The "_Phoedo_" enforces the supremacy of wisdom, and the "_Philebus_" the "_summum bonum_." _Love_ is the aspiration after a communion with perfection. The chief excellence of the philosophy which Plato taught, consists in the immutable basis assigned to the principles of moral truth; the defects are a want of distinct apprehension of the claims of divine justice in consequence of human sin, and an indirect discouragement of active virtue.