There is a phenomenon of anaphoric reference that makes it remote and so somewhat detached from the referent - many of the examples given in reply have this quality.

In the Melville quote "if only an easy outline one for the present" this is happening to a small degree. "one" could be replaced by the referent "popular comprehensive classification" or just "classification" and our memory will be eased by the repetition of the actual referent; or "one" could be eliminated altogether so that there is no anaphoric reference to exercise our memory.

I earlier said that there is a slight detachment of the anaphor: it is caused by the word "easy" qualifying "outline". Using "easy" causes a bit of a hiccup in our interpretation because what else should an outline be but easy - "easy" used here is a pleonasm. If "easy" is eliminated then "one" is less remote, and if both "easy" and "one" are eliminated there is no loss in understanding and our memory is less exercised.

There is a phenomenon of anaphoric reference that makes it remote and so somewhat detached from the referent - many of the examples given in reply have this quality.

Now the various species of whales need some sort of popular comprehensive classification, if only an easy outline one for the present,[...]

In Melville's quote this is happening to a small degree. "One" could be replaced by the referent "popular comprehensive classification" or just "classification" and our memory will be eased by the repetition of the actual referent; or "one" could be eliminated altogether so that there is no anaphoric reference to exercise our memory.

I earlier said that there is a slight detachment of the anaphor: it is caused by the word "easy" qualifying "outline". Using "easy" causes a bit of a hiccup in our interpretation because what else should an outline be but easy - "easy" used here is a pleonasm. If "easy" is eliminated then "one" is less remote, and if both "easy" and "one" are eliminated there is no loss in understanding and our memory is less exercised.