It is exclusive.
They see no more than this.

And thus they see unthinkably far, unthinkably keenly.
Most animals, however, smell what they see: vision is not very highly developed.

They know better by the more direct contact of scent.
And vision in us becomes faulty because we proceed too much in one mode.

We see too much, we attend too much.

The dark, glancing sightlessness of the intent savage, the narrowed vision of the cat, the single point of vision of the hawk--these we do not know any more.
We live far too much from the sympathetic centers, without the balance from the voluntary mode.