unknowable

X and Y could be terrible on their own, unknowable terms, and therefore incomparable.

He was always affable but ultimately unknowable; intellectually incurious but ferociously ambitious.

Doug Kenney was many things to many people—funny, generous, unknowable.

The Glassless will walk around with heads ducked down, desperate to avoid the mysterious, unknowable intentions of the Glassed.

“People are unknowable,” Hardy mutters—his last lesson for Miller.

One might almost say that the air, the invisible air, is full of unknowable Forces, whose mysterious presence we have to endure.

I have no intention of discussing here the philosophic value of the "Unknowable."

With this we can all agree, but it does not bring us any nearer an "unknowable."

We have already referred to the use made by religionists of Spencer's "Unknowable."

He bases all his knowledge upon his knowledge of "the unknowable."