he German philosopher Immanuel Kant (1724-1804) is generally credited with much of the foundational thought in the evolution of deontology and deontological perspectives. Kant viewed the ability of human beings to reason as the basis of our status as moral agents. Therefore, Kantian ethics rests on the argument that "morality is grounded in reason, not in tradition, intuition, conscience, emotion, or attitudes such as sympathy" (Beauchamp and Childress 2001). To be fully human is to be a rational being capable of exercising both reason and free will in making decisions and choosing actions.

Kant further believed that since we cannot control the outcome of our actions, the morality of an act cannot depend on the outcome or consequences, but must be judged based on the motive or intent of the actor. A moral action is one that is performed solely for the purpose of meeting a moral obligation, and the action itself can only be judged moral in light of the intention behind it. The actual outcome is not considered morally relevant.

Kant's test of whether an action meets a moral obligation is referred to as the categorical imperative. The basic formulation of this imperative is the test of universalizability, which states that you must act so that the rule or principle guiding your action can be willed to be a universal law. That is, could I take this action in all similar circumstances without being logically inconsistent? For example, telling a lie violates this maxim because you could not logically will that people be free to lie whenever they wanted without rendering the concept of truth useless. Therefore, truth telling becomes an important obligation or duty in this ethical perspective because the truth is one necessary condition for rational analysis.