From Alexander Pope’s Epistle to Cobham, lines 10-40 in vol 3, pt. 2 of the Twickenham edition, Epistles to Several Persons. The edition matters more than normal since maybe 1/4 of these lines will not appear in earlier printings:
Men may be read, as well as Books too much.
To Observations which ourselves we make,
We grow more partial for th’ observer’s sake;
To written Wisdom, as another’s, less:
Maxims are drawn from Notions, those from Guess.
There ’s some Peculiar in each leaf and grain,
Some unmark’d fibre, or some varying vein.
Shall only Men be taken in the gross?
Grant but as many sorts of Mind as Moss.*
That each from other differs, first confess;
Next, that he varies from himself no less:
And Nature’s, Custom’s, Reason’s, Passion’s strife,
And all Opinion’s colours cast on life.
Yet more; the diff’rence is as great between
The optics seeing, as the objects seen.
All Manners take a tincture from our own,
Or come discolour’d thro’ our Passions shown.
Or Fancy’s beam enlarges, multiplies,
Contracts, inverts, and gives ten thousand dyes.
Our depths who fathoms, or our shallows finds,
Quick whirls and shifting eddies of our minds?
Life’s stream for Observation will not stay,
It hurries all too fast to mark their way.
In vain sedate reflections we would make,
When half our knowledge we must snatch, not take.
On human actions reason tho’ you can,
It may be Reason, but it is not Man:
His Principle of action once explore,
That instant ’tis his Principle no more.
Like following life thro’ creatures you dissect,
You lose it in the moment you detect.
*The editor, Bateson, usefully points out via footnote that there are over 300 kinds of moss. I imagine that number has gone up since the edition’s first publication in 1954.