When I was an English literature undergraduate, we were all very careful to avoid what used to be called the ‘intentional fallacy’. This is the idea that you can use a text to get at what the author ‘really meant’. The so-called New Critics said, quite reasonably, that the text is all you’ve got to go on and, what’s more, it’s impertinent and irrelevant for a critic to start trying to figure out, say, whether Shakespeare is a racist from the evidence in ‘My mistress’ eyes are nothing like the sun’.