Full Idea
When first a man hath an appetite or will to something, to which immediately before he had no appetite or will, the cause of his will is not the will itself, but something else not in his own disposing.
Gist of Idea
If a man suddenly develops an intention of doing something, the cause is out of his control, not in his will
Source
Thomas Hobbes (Letters to the Lord Marquis of Newcastle [1652])
Book Reference
Hobbes,Thomas: 'Leviathan', ed/tr. Macpherson,C.B. [Penguin 1981], p.210