What Am I?

What an I, whence produced, and for what end?
Whence drew I being, to what period tend?
Am I th' abandon'd orphan of blind chance,
Dropp'd by wild atoms in disordered dance?
Or, from an endless chain of causes wrought,
And of unthinking substance, born with thought?
Am I but what I seem, mere felsh and blood,
A branching channel with a mazy flood?
The purple stream that through my vessels glides,
Dull and unconscious flows, like common tides,
The pipes, through which the circling juices stray,
Are not that thinking I, no more than they;
This frame, compacted with transcendent skill,
Of moving joints, obedient to my will;
Nursed from the fruitful glebe, like yonder tree,
Waxes and wastes, -- I call it mine, not me,
New matter still the mould'ring mass sustains;
The mansion chang'd, the tenant still remains;
And, from the fleeting stream, repair'd by food,
Distinct, as is the swimmer from the flood.

by Dr. Arbuthnot