[3] Phaedon is a series of three dialogues in which Socrates argues for the immortality of the soul, in preparation for his own death.

Many philosophers, including Plotinus, René Descartes, and Gottfried Wilhelm Leibniz, argued that the soul is simple.

Materialistic views were at the time common and fashionable, and faith in immortality was at a low ebb.

Phaedon became a bestseller upon its publication, earning Mendelssohn the nickname “Berlin Socrates” and “German Plato”.

[4][5] Kant criticized Mendelssohn's argument for immortality in the second edition of the Critique of Pure Reason (1787),[6] at B413-15.