In 1770, before he was 20, Maimon wrote an unorthodox commentary on Maimonides' Moreh nevukhim (The Guide for the Perplexed) that earned him the hostility of fellow Jews. At 25 he traveled to Königsberg, Prussia (now Kaliningrad, Russia), and wandered over Europe until he settled in Posen, Pol., as a tutor. His material insecurity ended in 1790, when he was given residence on the estate of Count Friedrich Adolf, Graf von Kalckreuth at Nieder-Siegersdorf. During the next decade he wrote his major philosophical works, including the autobiography edited for him by K.P. Moritz as Salomon Maimons Lebensgeschichte (1792; Solomon Maimon: An Autobiography, 1888) and his major critique of Kantian philosophy, Versuch über die Transcendentalphilosophie (1790; “Search for the Transcendental Philosophy”).

Despite his defection from the ranks of Kant's disciples, Maimon evoked praise from Kant for his criticism of the master philosopher, who declared that Maimon had understood his Critique of Pure Reason better than had any of his other critics. Maimon's Skepticism helped to establish the critical standards for approaching Kantian philosophy.

By emphasizing the limits of pure thought, Maimon also helped to advance philosophical discussion of the connection between thought and experience and between knowledge and faith. In his view there was religious and ethical value in the pursuit of truth, even though the goal itself was not completely attainable. His other major writings are Philosophisches Wörterbuch (1791; “Philosophical Dictionary”), Über die Progressen der Philosophie (1792; “On the Progresses of Philosophy”), and Kritische Untersuchungen über den menschlichen Geist (1797; “Critical Investigations of the Human Spirit”).