Full Idea
If you can only know what is intrinsically valuable through intuition (as Moore claims), you can still argue about what is unconditionally valuable. There must be something unconditionally valuable because there must be a source of value.
Gist of Idea
If we can't reason about value, we can reason about the unconditional source of value
Source
Christine M. Korsgaard (Aristotle and Kant on the Source of Value [1986], 8 'Three')
Book Reference
Korsgaard,Christine M.: 'Creating the Kingdom of Ends' [CUP 1996], p.228
A Reaction
If you only grasped the values through intuition, does that give you enough information to infer the dependence relations between values?