While Plato followed the morals of Socrates, he cultivated the metaphysical opinions of Pythagoras. He is said to have founded his physics on the notions of Heraclitus: it may be presumed, nevertheless, that he derived that branch of his system from a better source. ----- It is evident that Plato believed in the immortality of the soul of man; but he had, at the same time, very inadequate conceptions of the mode or state of its existence, when separated from the body. It seems to have been reserved for the Christian dispensation, to elucidate this great _arcanum_, hidden from the most sagacious of the heathen philosophers.[9] It was the difficulty that arose on this subject, the incapability of knowing how to dispose of the soul, or intellectual principle in the constitution of our species, after its disentanglement from the body; a difficulty by which all the philosophers, antecedent to the promulgation of Christianity, were subjected to unsurmountable perplexities;—it was this, that rendered even the expansive genius of Anaxagoras utterly incompetent to conceive of the possibility that the soul should exist, independent of some union with matter. He therefore invented the doctrine of the _Metempsychosis_; in order to provide some receptacle of organised matter for that imperishable intellectual principle attached to our nature here, after its departure from the human frame; and to which new vehicle of the vital spirit of its original but abandoned abode, the extinguished corporeal man, its union with it should impart the powers and faculties of animal life. ----- Footnote 9: “_Reason_, tho’ taught by sense to range on high, To trace the stars and measure all the sky; Tho’ fancy, memory, foresight fill her train, And o’er the beast he lifts the pride of man; Yet, still to _matter_, _form_ and _space_ confin’d, Or moral truths or laws that rule mankind, Could ne’er, _unaided_, pierce the mental gloom, Explore _new_ scenes _beyond the closing tomb_, Reach with _immortal_ hope the blest abode, Or raise one thought of _spirit_ or of GOD.” _Vision of Columbus_, book VIII. -----