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.
The one intelligible theory of the universe is that of objective idealism, that matter is effete mind, inveterate habits becoming physical laws (Peirce, CP 6.25).
The literal meaning of the word effete is no longer fruitful, hence it has the connotations of decadent, degenerate, exhausted, outmoded, weak, or worn out. In the light of Peirce's overall philosophy, the option degenerate may be singled out as the most likely synonym, interpreted to mean reduced in generative power. Thus matter is the flat, insipid, dyadic reduct of the triadic mind.