The main feature of subjective idealism is subjective spirit (human feelings, experience, ideas, will, mind, etc.). ) is regarded as the only real existence and the source of the world, and objective things and even the whole material world are the products of this subjective spirit. Subjective idealism will inevitably lead to solipsism. For example, British Archbishop Becquerel believes that the origin of the world is people's subjective feelings, and everything in the world is "a combination of feelings, and existence is perceived"; Mach advocates that "the world is a combination of sensory elements"; Kant's "human reason legislates for nature"; Descartes' "I think, therefore I am"; Nietzsche's "the will of natural selection is above everything else"; Schopenhauer's "will is the object of the world, and will is the root of all existence and movement"; Bogdanov's "experience is the ultimate component of the world"; Dewey's "The world is my idea, my experience". Zhuangzi in ancient China said that "everything is one with me"; Mencius said that "everything is ready, only the east wind is needed"; Lu Xiangshan said that "the universe is my heart, and my heart is the universe"; Wang Yangming said that "nothing is unintentional, everything is in the pericardium, everything is in the pericardium, everything is in my heart" and so on, which are typical representatives of subjective idealism.

The main feature of objective idealism is to combine a kind of spirit (rationality, idea, universal spirit, absolute idea, absolute spirit, etc. ) that is, it becomes an independent objective existence without matter and any individual, and regards it as the source of the world and the creator of all things. It holds that the origin of the world is not the subjective spirit of human beings, but the objective spirit of hyperspace, and all things and phenomena in the world are derivatives or manifestations of this spiritual entity. The absurdity of objective idealism lies in the philosophical recognition of "religious creationism", and its so-called objective spirit is just an alias of God. For example, in the19th century, the German philosopher Hegel believed that "the world is the alienation of absolute concept, the material world is the externalization of absolute spirit, and the concept of contract is the origin of everything"; Plato's "ideal world is the shadow of the real world", "the world is God's demonstrable creation" and "man is dominated by fate". Laozi, an ancient philosopher in China, said, "Tao is the root of heaven and earth, the mother of all things, the Tao gives birth to one, two, three, three and all things, and the Tao gives birth to all things"; He Yi's "everything has a reason, there must be anger in reason, and there must be days in reason"; Zhu believes that "reason comes before things, reason comes first, and reason is the foundation of everything", which is a typical representative of objective idealism.