In Sonnet 147, William Shakespeare brings together two themes that have agitated him before: firstly the at the time fairly commonplace notion of love – and, more to the point, desire – as a disease that weakens the mind to the point of an irrational madness and afflicts the body in a similarly stark fashion, and secondly the ways in which his mistress deviates from the ordinarily praised ideal of beauty.

The sonnet therefore returns the series firmly and identifiably to the 'Dark Lady' and the effect she is having on our poet in an unequivocally physical manner, leaving behind the reflections on the soul of the previous sonnet and concerning itself once more with his lust for someone he knows – or at the very least declares – to be neither traditionally beautiful nor morally sound.