[t1tos]

"Nature, then, has carefully cultivated the seed within the hard core--namely the urge for and the vocation of free thought."

Kant may be referring to the liberation of political nonage. The illusion of open discourse with the necessity to obey is the mark of a slighted man in the sovereign. So he urges us: "Caesar has no power over grammarians."

[zogrodea]

That might be the content of what Kant is speaking about, but I think the method/process of what he is speaking about is interesting and deserving of attention too.

"Thanks be to Nature, then, for the incompatibility, for heartless competitive vanity, for the insatiable desire to possess and to rule! Without them, all the excellent natural capacities of humanity would forever sleep, undeveloped. Man wishes concord; but Nature knows better what is good for the race; she wills discord. He wishes to live comfortably and pleasantly; Nature wills that he should be plunged from sloth and passive contentment into labor and trouble, in order that he may find means of extricating himself from them. The natural urges to this, the sources of unsociableness and mutual opposition from which so many evils arise, drive men to new exertions of their forces and thus to the manifold development of their capacities. They thereby perhaps show the ordering of a wise Creator and not the hand of an evil spirit, who bungled in his great work or spoiled it out of envy."

From https://en.wikisource.org/wiki/Idea_for_a_Universal_History_... (under the heading "FOURTH THESIS").

I can certainly relate to his statement that labour and trouble have enhanced my capabilities and others here likely can as well.