Moore argued that, once arguments based on the naturalistic fallacy had been discarded, questions of intrinsic goodness could be settled only by appeal to what he (following Sidgwick) called "moral intuitions": self-evident propositions which recommend themselves to moral reflection, but which are not susceptible to either direct proof or disproof ("Principia", § 45). As a result of his view, he has often been described by later writers as an advocate of ethical intuitionism. Moore, however, wished to distinguish his view from the views usually described as "Intuitionist" when "Principia Ethica" was written: