After Europe entered feudal society, the theory of natural human nature was submerged and denied by the theory of human nature in religious theology. It was not until the Renaissance that the theory of natural human nature was revived. The thinkers and artists of this period all shifted their focus from God to humans, to human nature, and to the secular spirit of the world. For example, Boccaccio clearly affirmed that human emotions and desires are human nature and cannot be suppressed or avoided. He believed that human beings are inherently equal.

The thoughts of human nature of modern European Enlightenment scholars were developed on the basis of the Renaissance criticism of medieval religious theology that used divinity to deny human nature and replaced it with human nature that negated divinity. Theorists of natural human nature in modern Europe almost unanimously believe that human beings are products of nature. Human nature is to pursue happiness and joy and to avoid pain and disaster. Therefore, self-preservation and selfishness are natural. Of course, each thinker also has his or her own opinions. For example, Thomas Hobbes strongly believed that human nature is selfish and evil. His famous saying is: "People are like wolves to others." Holbach further pointed out that human nature is to love oneself, but if people want to live harmoniously, they must do one thing: they have obtained their natural rights. And without harming others at all. Loving others is a means to make yourself happy, because people's happiness is related to each other. Rousseau believed that human nature is innate, and the first law of this innate nature is self-love. Self-interest and self-love are rights given by God. This natural human right is inviolable, based on human nature, and cannot be given up. However, he believed that people not only have self-love, but also compassion.

Europe’s modern Enlightenment thinkers used the theory of human nature as a weapon to oppose theological idealism and feudal despotism, used human nature to oppose divinity, and used the natural nature of self-love and self-interest to oppose asceticism. These are all progressive. But they understand man as just a natural animal. But human nature is only one aspect of multidimensional human nature. They do not understand the fundamental role that social life and social practice play on human nature.

Among the natural human nature theorists, some believe that human nature is inherently evil, so external social norms need to be used to enforce restraint. However, there are also some thinkers who derived hedonism and hedonistic outlook on life from the theory of natural human nature. They advocate living according to nature and conforming to nature. The ancient Greek thinker Democritus believed that people's sensory needs should be satisfied and considered this a requirement for happiness and happiness. Other natural human nature theorists such as Heraclitus, Epicurus, Lucretius, etc. also regard the pursuit of pleasure and avoidance of pain as human nature, and believe that happiness is the pursuit of sensual pleasure and the avoidance of pain. Of course, they also see that human happiness must also include spiritual happiness. Feuerbach, the German sensualist humanistic theorist, insisted that the pursuit of happiness in perceptual life is the ultimate innate nature of humans and living things. However, overemphasis on human physical needs, everything starts from and ends here, and leads to hedonistic conclusions. This is the failure of the naturalistic theory of sensory happiness. It produces a low-level guidance in people's pursuit of life. In theory, it is also a misunderstanding of human nature, life, and human happiness. However, it affirms human needs in terms of natural attributes, which are reasonable. Another theoretical shortcoming of sensoryism is that it does not answer the contradictory question of personal happiness and social happiness. Therefore, the theory of sensory happiness and the principle of egoism have been attacked by thinkers who advocate rationality and virtue and criticized by thinkers who emphasize the social attributes of human beings.

What should be emphasized here is that the natural attributes of human beings and the theory of natural human nature are two completely different issues. "Natural attributes" mainly refer to people's natural desires and physiological functions. From a philosophical point of view, they are the relationship between the mermaid's own animal nature. But as a human being, his natural attributes no longer have the meaning of independent existence. For animals, people can consciously understand the laws of nature and actively transform the natural world. In short, on the one hand, human beings are natural, beings limited by time and space, specific natural conditions, and their own form of existence. At the same time, they are the main body of the social and cultural world. They are a kind of being who can master the world and create a social culture that is different from nature. A living being.

Emphasizing that people are rational and that people should live a rational and controlled life has already been put forward by the early Greeks, such as Pythagoras, Socrates, etc., who all advocated that people should live under rational control. However, when discussing people The rational theory of human nature can be traced back to Plato's "idea" thought.