This document provides an overview of Immanuel Kant's moral philosophy and the concept of the "good will." It discusses that for Kant, the only thing that is absolutely good is a good will. A good will is motivated by duty alone, without external influences like desires, emotions, or consequences. The document also examines Kant's categorical imperative and its four formulations, including the universalizability formulation which states we should only act on maxims we can universalize. It provides examples of how stealing could not be universalized but telling the truth could. Finally, it briefly introduces Kant's deontological moral theory which holds we have duties to act in accordance with moral rules and principles.