Full Idea
Whatever is logically necessary must be reflected in a corresponding transcendental necessity. But there are a great range of transcendental necessities which are not reflected in any logical necessity.
Gist of Idea
There is a transcendental necessity for each logical necessity, but the transcendental extends further
Source
Harré,R./Madden,E.H. (Causal Powers [1975], 1.V.C)
Book Reference
Harré,R/Madden,E.H.: 'Causal Powers: A Theory of Natural Necessity' [Blackwell 1975], p.21
A Reaction
That is, the world would be unknowable if any of the logical necessities failed to apply to it. I hope that doesn't mean that we are supposed to intuitively know all the logical necessities. Nowadays we are famous for being bad at that.
Related Idea
Idea 15231 Transcendental necessity is conditions of a world required for a rational being to know its nature [Harré/Madden]