 As a branch of logic, deontic logic is of theoretical interest for some of the same reasons that  modal logic  (the logic of necessity and possibility), is of theoretical interest. Also, although we need to be cautious about making too easy a link between deontic logic and practicality, many of the notions listed above are typically employed in attempting to regulate and coordinate our  lives.[4]  For these reasons, deontic logics often directly involve topics of considerable practical significance such as morality, law, social and business organizations (their norms, as well as their normative constitution), and security systems. To that extent, studying the logic of notions with such practical significance adds practical significance to deontic logic itself. However, in this entry we will focus on deontic logic itself, rather than its applications and practical relevance.