In faith I do not love thee with mine eyes
For they in thee a thousand errors note;
But 'tis my heart that loves what they despise
Who, in despite of view, is pleased to dote
Nor are mine ears with thy tongue's tune delighted;
Nor tender feeling, to base touches prone
Nor taste, nor smell, desire to be invited
To any sensual feast with thee alone:
But my five wits nor my five senses can
Dissuade one foolish heart from serving thee
Who leaves unswayed the likeness of a man
Thy proud heart's slave and vassal wretch to be:
In Shakespeare’s time what was called the “Five Wits” would be the modern Five Senses — the tools of human perception.  The wits were “ common wit, imagination, fantasy, estimation, and memory .” “ Estimation ” is today’s  instinct ,  “ imagination ” would be close to  thinking , and “ common wit ” is what we call  common sense . 
 This is also the  volta  of the sonnet. It begins, typically, with the negative conjunction “But,” and repeats the “nor” from the second quatrain to change the trajectory of the argument and move towards the resolution.
Sonnet 141