Being an answer to the question proposed for consideration by the Berlin Royal Academy of Sciences for the year 1763

Introduction

The question proposed for consideration is such that, if it is appropriately answered, higher philosophy must as a result acquire a determine form. If the method for attaining the highest possible degree of certainty in this type of cognition has been established, and if the nature of this kind of conviction has been properly understood, then the following effect will be produced: the endless instability of opinions and scholarly sects will be replaced by an immutable rule which will govern didactic method and unite reflective minds in a single effort. It was in this way that, in natural science, Newton's method transformed the chaos of physical hypotheses into a secure procedure based on experience and geometry. But what method is this treatise itself to adopt, granted that it is a treatise in which metaphysics is to be shown the true degree of certainty to which it may aspire, as well as the path by which the certainty may be attained? If what is presented in this treatise is itself metaphysics, then the judgment of the treatise will be no more certain than has been that science which hopes to benefit from our inquiry by acquiring some permanence and stability; and then all our efforts will have been in vain.