Far as creation's ample range extends,
The scale of sensual, mental powers ascends:
Mark how it mounts to man's imperial race,
From the green myriads in the peopled grass:
What modes of sight betwixt each wide extreme,
The mole's dim curtain, and the lynx's beam:
Of smell, the headlong lioness between,
And hound sagacious on the tainted green:
Of hearing, from the life that fills the flood,
To that which warbles through the vernal wood?
The spider's touch, how exquisitely fine!
Feels at each thread, and lives along the line:
In the nice bee, what sense so subtly true
From poisonous herbs extracts the healing dew?
How instinct varies in the grov'ling swine,
Compared, half-reasoning elephant, with thine!
'Twixt that and reason, what a nice barrier
For ever separate, yet for ever near!
Remembrance and reflection, how allied;
What thin partitions sense from thought divide;
And middle natures, how they long to join,
Yet never pass the insuperable line!
Without this just gradation could they be
Subjected, these to those, or all to thee?
The powers of all subdued by thee alone,
Is not thy reason all these powers in one?
Alexander Pope, 1688-1744