Immanuel Kant was an 18th Century German philosopher, who took the rationalistic (reason-derived) approach to ethics and morality. Kant believed that us humans were rational agents, and just as we can draw a triangle based on the ‘idea’ of a Triangle that we have in our minds, that of an objective reality; it follows, that our actions can derive from an objective morality.
Grounding moral behaviour in rationality was what he considered to be the “Copernican revolution” in ethics and this is where his brain-child, the Categorical Imperative, emerged. A rule which binds all rational agents together by a simple rule or maxim: “Act only according to a rule, which you can at the same wish that it could become a universal law.”
Morality, to Kant, is deontological or deriving from duty. Due to our capability to reason – which Kant places upon a pedestal – it is the motive behind an action, which is more important than its outcome. With this in mind, Kant proposed a powerfully explicit, unflinching theory which combatted the perception of morals being purely subjective. Reason is what helps us to transcend cultural and racial boundaries and it grandly unifies our behaviour towards one other.