 Insofar as Kant professed embarrassment about his pre-1770 essays, it might be tempting to divide his discussion of Leibniz into a pre-critical (before 1770) and a critical phase. Yet this division is not specially illuminating, and recent scholars have questioned the formerly standard periodization (see the entry on  Kant’s philosophical development).  The True Measurement of Living Forces, (1747), the Physical Monadology (1756), New Elucidation (1755), the Essay on some Treatments of Optimism (1759), Negative Quantities (1763) and the Dreams of a Spirit-Seer (1766) are all technically “pre-critical,” but they are critical with respect to logical, physical, and theological Leibnizian principles and doctrines. It is plausible to see the “silent decade” between 1771 and 1780 as the interval in which Kant decided how to manage the skeptical problem he now saw as threatening morality, arriving finally at the positive philosophy in the Critique of Pure Reason (1781) which steers (perhaps only temporarily, judging by the Opus Postumum) a middle course between visionary and mystical enthusiasm and skepticism. Kant’s further thoughts on Leibniz were developed in the Metaphysical Foundations of Natural Science (1786), the polemical essays, On a Discovery According to which any Critique of Pure Reason has been made Superfluous by an Earlier One (1790) and What Progress has Metaphysics Made in Germany since the Time of Leibniz and Wolff?(1791), and in the Critique of Judgement (1790).