Kant's discussion of the Eighth Proposition of the Idea for a Universal History with a Cosmopolitan Aim marks an all-important turning point of his entire argument. Let us first take note of the proposition itself.

This Proposition, Kant states, is a consequence of the previous one. Indeed, lawful external relations between states such as to make wars between them unnecessary are a prerequisite for a stable civil society in which reason can flourish. For reason, Kant had stated in the Second Proposition, can develop fully only in the species, but not in the individual. Its development requires favorable conditions in society, which can only be fulfilled if a certain amount of international stability prevails.

As a human capacity reason is still a product of nature. It is what distinguishes us from all the other natural creatures. Most animals are endowed by nature with species-specific instincts (or organs) that guide their struggle for survival. Humans, by contrast, were initially endowed by nature only with those instincts that belong to animals in general – sexual instincts, instinct for food, etc. – but with none that were specific to their species.