Full Idea
If a covenant is made with neither party performing presently, but trust one another, in the condition of mere nature (which is war between men) upon reasonable suspicion, it is void.
Gist of Idea
In the violent state of nature, the merest suspicion is enough to justify breaking a contract
Source
Thomas Hobbes (Leviathan [1651], 1.14)
Book Reference
Hobbes,Thomas: 'Leviathan', ed/tr. Macpherson,C.B. [Penguin 1981], p.196