The present collection of studies deals with normative reasoning. The first two essay are concerned with Leibniz’s cry for opposing to conventional logical dedection other more flexible form of “defeasible” or common-sense reasoning, very much in the spirit of the “nonmonotonic” or “common-sense” logics now fashion in the so-called Artificial Intelligence & Law field. The third essay aims to clarify the logic of the concept of (legal) presumption. The fourth essay deals with automated deduction in normative (deontic) logic. The subsequent three essay deal with the problem of providing an algorithmic framework for mechanising defeasible forms of normative reasoning. Finally the last essay is concerned with some non-logical aspects of normative reasoning.