re: A Poison Tree, by William Blake. Let’s talk about what this means

First of all, Blake was mentally ill. It’s why a lot of his poems suggest he was drugged out of his gourd.

Second, this poem is at least partially about anger, and not holding it in. Anger needs to be let out, to be expressed and seen instead of held in, poisoning you.

As I recall, it’s original title had something to do with Christianity.