Question

Which lines are the best example of parallelism?

Placed on this isthmus of a middle state,
A being darkly wise, and rudely great:
With too much knowledge for the sceptic side,
With too much weakness for the stoic’s pride
As Eastern priests in giddy circles run,
And turn their heads to imitate the sun.
Admired such wisdom in an earthly shape
And showed a Newton as we show an ape.

Answer 1

Lines 3–4:

"With too much knowledge for the sceptic side,
With too much weakness for the stoic’s pride."

They repeat the same grammatical pattern ("With too much ... for the ...") to set up a balanced contrast, which is the hallmark of parallelism.