Objective idealism is an idealistic metaphysics that postulates that there is in an important sense only one perceiver, and that this perceiver is one with that which is perceived. One important advocate of such a metaphysics, Josiah Royce, wrote that he was indifferent "whether anybody calls all this Theism or Pantheism". Plato is regarded as one of the earliest representatives of objective idealism. It is distinct from the subjective idealism of George Berkeley, and it abandons the thing-in-itself of Kant's dualism.