Full Idea
The state of nature is a state of war. For even if it does not involve active hostilities, it involves a constant threat of their breaking out.
Gist of Idea
The state of nature always involves the threat of war
Source
Immanuel Kant (Perpetual Peace [1795], 2)
A Reaction
Kant is siding with Hobbes against Rousseau, despite Rousseau's claim that Hobbes's pessimism concerns a more advanced situation that the true (and peaceful) state of nature.
Book Reference
Kant,Immanuel: 'Political Writings', ed/tr. Reiss,Hans [CUP 1996], p.98