For example, in the veil of ignorance, John Rawls asks us to imagine a group of persons in a situation where they know nothing about themselves, and are charged with devising a social or political organization. The use of the state of nature to imagine the origins of government, as by Thomas Hobbes and John Locke, may also be considered a thought experiment. Søren Kierkegaard explored the possible ethical and religious implications of Abraham's binding of Isaac in "Fear and Trembling". Similarly, Friedrich Nietzsche, in "On the Genealogy of Morals", speculated about the historical development of Judeo-Christian morality, with the intent of questioning its legitimacy.