There is not much in The Open Society to suggest that Karl Popper was a moral objectivist. Yet, that is exactly what he himself claimed later in life. Was the widespread “decisionistic” reading of The Open Society just a grand misunderstanding, or did Popper change his metaethical views without acknowledging it? I give reasons as to why we should hold the latter to be true. I also argue that even were the former the case, decisionism would still be more compatible with the open society ideal.
Critical dualism, Is-ought, Karl Popper, Moral objectivism, Moral relativism, Open society