Full Idea
It is natural to assume that if we can compare two objects or states of affairs, X and Y, then X is either better than, or worse than, or as good as Y. This has been called the Trichotomy Thesis.
Gist of Idea
Trichotomy Thesis: comparable values must be better, worse or the same
Source
Francesco Orsi (Value Theory [2015], 6.2)
Book Reference
Orsi,Francesco: 'Value Theory' [Bloomsbury 2015], p.102
A Reaction
This is the obvious starting point for a discussion of the difficult question of the extent to which values can be compared. Orsi says even if there was only one value, like pleasure, it might have incommensurable aspects like duration and intensity.