Kant's pre-critical period is commonly considered to run from 1747 when he published On the True Estimate of Living Fortes to the appearance in 1770 of his inaugural dissertation, On the Form and Principle of the Sensible and the Intellectual Worlds. It is in this period that the origins of his later system of ethical thought can be found. Yet there is very little literature in English dealing with this early period and many secondary sources deal only with his later major ethical works the Critique of Practical Reason and Groundwork of the Metaphysic of Morals.Schilpp's book aims, in presenting the pre-critical writings, to show that ethics was a central preoccupation for Kant long before the second Critique. His evidence draws together materials not only from Kant's early published writings but also from unfinished fragments, lecture notes and correspondence. The result is a thorough investigation of the development of Kant's moral philosophy prior to the publication of the first Critique. It will make the reader re-examine Kant's ethical thought as a whole and, in doing so, find a stronger and more rational interpretation.