Classic Poem

What is that to fire nor earth,
Aire nor water owes its birth,
Yet to his unbounded force
Each of these submits its course,
Whose first liberty confind
With its selfe the free borne mind?
Shortest when the day is longest,
Weakest [when its beames are strongest;]
Which though blind pursues the light,
Though it want yet wounds with sight?
Who this knowst not, seek not out
To untye this Mystick doubt,
Nor esteeme thy selfe lesse wise
That from thee conceald it lies;
Others Knowledge may advance,
Skill lies here in ignorance.