We can know only what came out of his work, never what went into it

From Shakespeare The World as Stage by Bill Bryson. Page 16.

Other, literal-minded readers of Shakespeare’s sonnets have been struck by two references to lameness, specifi cally in Sonnet 37:

As a decrepit father takes delight
To see his active child do deeds of youth,
So I, made lame by Fortune’s dearest spite,
Take all my comfort of thy worth and truth.

And again in Sonnet 89:

Say that thou didst forsake me for some fault,
And I will comment upon that offense.
Speak of my lameness, and I straight will halt.

and concluded that he was crippled.

In fact it cannot be emphasized too strenuously that there is nothing—not a scrap, not a mote—that gives any certain insight into Shakespeare’s feelings or beliefs as a private person. We can know only what came out of his work, never what went into it.

I wonder if the latter ought not be a guiding principle. We often wrestle with whether the product of a creator (artist, poet, author, musician, scientist, discoverer, etc.) is tainted by how that person lived their life, crimes they might have committed, etc.

I am inclined to acknowledge the dilemma and then dismiss it. Even contemporary history is subject to revision and reassessment: our knowledge is never certain. More critically, progress is always based on the work of those who came before us. To abandon their incremental additions because of some defect of character is to bring progress to a halt, indeed, to revert to savagery. We can only measure with certainty what came out of their work, never what went in to it.