Full Idea
Objective idealists such as Bradley (rather than Berkeley's subjective view) accepted the substantial existence of reality (which they called the 'Absolute') but held that thought cannot fully describe it.
Gist of Idea
Bradley's objective idealism accepts reality (the Absolute), but says we can't fully describe it
Source
report of F.H. Bradley (Appearance and Reality [1893]) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 23 'Abs'
Book Reference
Potter,Michael: 'The Rise of Anaytic Philosophy 1879-1930' [Routledge 2020], p.151
A Reaction
That thought can't 'fully' describe it seems obvious, so I suspect Bradley's view are stronger than that. This sounds like modern strong and weak anti-realists; strong ones deny reality, but weak ones just deny we know where the joints are.