photo credit: Bigstock The mice in my absence have been at my books again, with what Marx called, with regard to the manuscript of his then-unpublished Ludwig Feuerbach and the End of Classical German Philosophy, their gnawing criticism. Much good may gnawing it have done them! When finally published, forty years after it was written, the manuscript did considerable harm, at least if ideas have consequences, for as an appendix to that work is inscribed one of the most beguiling and pernicious of all epistemological doctrines, namely that people’s ideas are simply the reflection of their interests; from which it follows that, since people’s interests are different and irreconcilably opposed, the only real argument is violence. And we all know what that idea led to.