“FROM SUCH CROOKED TIMBER AS HUMANKIND IS MADE OF NOTHING ENTIRELY STRAIGHT CAN BE MADE”

In the Sixth Proposition of the essay Idea for a Universal History with a Cosmopolitan Aim (1784) Kant famously states that “From such crooked timber as humankind is made of nothing entirely straight can be made.” That humankind is made from crooked timber is why the Sixth Proposition says that the problem described in the Fifth Proposition “is both the hardest and the last that will be solved by the human species,” and one to the solution of which we can never expect more than an “approximation” or “gradual approach” (Annäherung) (Idea 8:23). But it is not clear why humankind's being made of crooked timber should cause the problem described in the Fifth Proposition to be so difficult to solve and indeed impossible to solve entirely. For what the Fifth Proposition says is that “The greatest problem for the human species, to the solution of which it is compelled by nature, is the attainment of a civil society administering justice universally” (8:23). Yet the administration of justice in civil society seems to be designed precisely to deal with the fact that humankind is made of crooked timber, for such administration is designed to enforce the universal principle of right (to “so act externally that the free use of your choice can coexist with the freedom of everyone in accordance with a universal law” [MS, Doctrine of Right, Introduction, section C, 6:231]) by external and coercive or aversive incentives (MS, Introduction, section IV, 6:219) precisely because people cannot be counted on to comply with this principle merely from respect for the moral law (although the universal principle of right is nevertheless ultimately grounded in the moral law).