Final answer:
The unconditional command of reason that must be obeyed without questioning in philosophy is known as a categorical imperative, encompassing universal moral laws discerned by reason and obligating action in accordance with moral universality.
Step-by-step explanation:
The unconditional command of reason that one must obey without questioning is known as a categorical imperative. This concept was extensively developed by the Enlightenment philosopher Immanuel Kant, who contended that categorical imperatives are universal laws discerned by reason and are thus obligatory regardless of personal desires. Unlike hypothetical imperatives, which are conditional and often tied to a personal goal or desire, categorical imperatives are derived from the structure of reason itself and imply an absolute moral duty.
An important example of a categorical imperative is Kant's principle: "Act only according to that maxim whereby you can, at the same time, will that it should become a universal law." Essentially, this means that one should only engage in actions that could be willed to be universal without contradiction. This implies that our actions should be consistent with the kind of world we would deem reasonable for everyone to live in, embodying moral universality.
In the broader context of ethics and law, the idea of an unconditional command can be found in various philosophical discourses. For example, in Thomas Hobbes's social contract theory, the laws of nature, which are discernible through human reason, are seen as binding commands. Similarly, in moral theologies like the divine command theory, morality is framed as commands from a higher authority which are to be followed unconditionally.