O! Reason! vaunted Sovreign of the mind!
Thou pompous vision with a sounding name!
Can'st thou, the soul's rebellious passions tame!
Can'st thou in spells the vagrant fancy bind?
Ah, no! capricious as the wav'ring wind,
Are sighs of Love that dim thy boasted flame,
While Folly's torch consumes the wreath of fame,
And Pleasure's hands the sheaves of truth unbind.
Press'd by the storms of Fate, hope shrinks and dies;
Frenzy darts forth in mightiest ills array'd;
Around thy throne destructive tumults rise,
And hell-fraught jealousies, thy rights invade!
Then, what art thou? O! Idol of the wise!
A visionary theme!--a gorgeous shade!

Mary Darby Robinson

http://www.poemhunter.com/poem/sonnet-xi-o-reason/