Full Idea
If men are their own judges of what conduces to their preservation, ..all men make different decisions about what counts as a danger, so (for Hobbes) the grimmest version of ethical relativism seems to be the only possible ethical vision.
Gist of Idea
Self-preservation is basic, and people judge differently about that, implying ethical relativism
Source
report of Thomas Hobbes (The Elements of Law [1640]) by Richard Tuck - Hobbes Ch.2
Book Reference
Tuck,Richard: 'Hobbes: a very short introduction' [OUP 2002], p.74
A Reaction
This might depend on self-preservation being the only fundamental value. But if self-preservation is not a pressing issue, presumably other values might come into play, some of them less concerned with the individual's own interests.