康德最初描述的定言令式是这样一种理论，即一个人"只能按照自己的原则行事" "通过这个原则，你可以同时希望它成为普遍法则"他认为，个人之所以能够以道德的方式行事，是因为他们在做出选择时能够理性自由地思考。他认为一个人的道德义务是绝对必要的，因为我们的道德告诉我们应该如何行动。他强调，这些道德责任命令我们采取某些行动，从而给我们一个词势在必行(Smith, 2010)。康德还认为，这些道德责任之所以与个体相关，是因为个体具有理性，而且个体有能力在不受他人影响的情况下做出自己的决定。本文将探讨他的定言令式在康德伦理学中的作用以及对其理论的局限性，从而得出定言令式可能是一种指导思想，但在现实世界中不能普遍而公正地应用的结论。康德的伦理学似乎是建立在我们每个人都有权享有自由、自治和民主的基础上的。因为这些权利是我们的，所以我们有能力作出自由、理性和道德的选择。我们可以通过推理能力来确定我们的责任。康德认为，定言令式以人类具有自由意志和推理能力为前提。康德的解释是有道理的，因为他认为，为了采取道德的行为，一个人首先必须有道德或不道德的选择的自由(Smith, 2010)。他还认为，作为理性的存在，个体是被理性所迫而遵循社会的规范和要求的，因此，我们理性的道德遵循着一套内在的规律，而这些内在的规律又支配着我们的行为。
The Categorical Imperative which was initially described by Immanuel Kant is the theory that a person is to “act only on the maxim through which you can at the same time will that it should become a universal law. He believed that individuals are able to behave in a moral way due to their ability to think rationally and freely when making choices. He felt that a person’s moral duties are categorical imperatives, in that our morals tell us how we ought to act. He stressed that these moral duties command us to take certain actions – thus giving us the word imperative (Smith, 2010). Kant also felt that these moral responsibilities are relevant to individuals because of their rationality and because individuals have the ability to make their own decisions apart from others influence. The role of his categorical imperative within Kant’s ethics will be discussed in this essay as well as the limitations to his theory, leading to the conclusion that the categorical imperative may be a guiding ideal, but cannot be universally and fairly applied in the real world.Kant’s ethics seem grounded in the basis of the idea that we each have rights to freedom, autonomy and democracy. Because these rights are ours, we therefore have the ability to make free, rational and moral choice. We can determine our duty through our ability to reason. Kant contends that the categorical imperative begins with the premise that human beings have a free will and that ability to reason. Kant’s explanations make sense because he argued that in order to act morally, it was necessary for one to first be free to have the choice of being moral or immoral (Smith, 2010). He also felt that as rational beings, individuals are compelled through their rationality to follow norms and requirements in society, thus our reasoned morality follows a set of internal laws which will then govern our actions.