Alike in what it gives, and what denies?

VII. Far as Creation's ample range extends,
The scale of sensual, mental pow'rs ascends:
Mark how it mounts, to Man's imperial race,
From the green myriads in the peopled grass: 210
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, 215
To that which warbles thro' 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 pois'nous herbs extracts the healing dew? 220
How Instinct varies in the grov'lling swine,
Compar'd, half-reas'ning elephant, with thine!
'Twixt that, and Reason, what a nice barrier,
For ever sep'rate, yet for ever near!
Remembrance and Reflection how ally'd; 225
What thin partitions Sense from Thought divide:
And Middle natures, how they long to join,
Yet never pass th' insuperable line!
Without this just gradation, could they be
Subjected, these to those, or all to thee? 230
The pow'rs of all subdu'd by thee alone,
Is not thy Reason all these pow'rs in one?

VIII. See, thro' this air, this ocean, and this earth,