As we all know, the primitive form of western philosophy is the natural philosophy of ancient Greece. In this embryonic period of western philosophy, philosophers mainly focus on the discussion of the nature of the universe. Most of their works are titled "On Nature", and they are usually called natural philosophers. When early Greek philosophy explained how all natural things came into being and existed, it always regarded the unity of infinite diversity of natural phenomena as self-evident, and looked for this unity from something special.
The natural philosophy of early Greece had a strong scientific spirit from the beginning. The earliest Greek philosopher and the first batch of scientists. On the other hand, because this philosophy has just been born from myth, it is inevitably branded as the mother. But on the whole, natural philosophers insist on explaining the nature of the universe from nature itself, and begin to get rid of the mystery of the creation myth of the universe, which marks the initial awakening of human scientific thinking. For example, Heraclitus inherited the materialistic tradition of Miletus School, and thought that everything contained opposition, pointing out: "Nature also pursues opposition, and it produces harmony from opposition, not from the same thing." [2] The Pythagorean school also regards "harmony" as the best thing in the world and a virtue of life, which reflects its school's grasp of the "number" of the unity of all things in the universe and its pursuit of the ideal state of moral perfection and social equality. From here, we can find the initial germination of exploring the natural view of the universe and the historical view of life.
Even the existential philosophy of Elijah School in early Greek philosophy, though highly speculative, actually answered the original question of the creation of all things in the world in the form of natural philosophy. The category of "being" put forward by parmenides is a philosophical abstract generalization of nature. In On Nature, he deepened the basic proposition of natural philosophy by logical argumentation and speculation.
Democritus's atomism is the highest achievement of ancient Greek natural philosophy. After parmenides, the characteristic of natural philosophy is to regard things as a composite and begin to explore the deeper internal structure of matter. Democritus's atomism thinks that the origin and internal structure of everything are atoms and "void", and puts forward the view that atoms move by themselves, trying to reinterpret some natural phenomena that early naive materialists can't explain. In these explanations, democritus emphasized that "everything is produced by necessity" [3], that is, he clearly put forward the causal inevitability of natural phenomena and expressed materialistic determinism. However, democritus separated the relationship between inevitability and contingency, simplified and exaggerated causal inevitability, and denied the objective existence of contingency. His determinism is mechanistic.
In this regard, Aristotle criticized: "democritus ignored the reason of purpose and attributed all the functions of nature to inevitability." [4] But it is worth noting that democritus skillfully used atomism to explain the composition of the soul, and linked the soul theory with the wisdom of life, which made his view of history reach a high level. In his remaining works, there are many proverbs that reveal the meaning of life: "Those who look forward to the goodness of the soul pursue sacred things, while those who pursue physical happiness have only one advantage, that is, they are easily disillusioned." [5] "We should be enthusiastic about doing things according to morality, not talking about morality." [6] "untimely happiness produces disgust." [7] "It is justified to pursue beauty without blaspheming it." [8] He added, "Ignorance of goodness is the reason for making mistakes." [9] "Always inventing beautiful things is a sign of the sacred mind." [10] "Ill-gotten wealth is harmful to morality." [1 1] In short, democritus's exploration of the true meaning of life taught people to pursue truth, goodness and beauty, and to abandon falsehood, ugliness and evil, thus leaving people with many things worth thinking about.
Of course, the philosophical form before Socrates is basically natural philosophy. Generally speaking, natural philosophy explores the mysteries of nature, pursues the origin of all things, and tries to unify the world with perceptual things. Socrates believes that natural philosophers are actually unreliable based on what the senses see, but they blind the eyes of the soul. He advocated that "it is better to seek help from the spiritual world and go there to seek the truth of existence." [12] In Socrates' view, the object of philosophy is not nature, but the mind, which is to know the goodness in oneself, that is, human virtue. This is Socrates' conclusion from his criticism of natural philosophy, which changed the research direction of ancient Greek philosophy, that is, from paying attention to the natural view of nature to the historical outlook on life.
In other words, Socrates' philosophy no longer pays attention to nature, but to life, that is, to seek a universal thing in ethics. However, Socrates did not completely separate the common things from the individual things. Plato advanced along this line of thought, not only separating the two, but also treating common things as the idea of independent existence. Plato believes that all concrete things experienced by human senses are constant, which has been proved by Heraclitus' rheological theory. The existence or non-existence of "unchangeable" phenomenon is relative, unstable and temporary. Absolute, stable and eternal ideas are the only real existence, and individual things are just imitations and shadows of ideas. Because of this philosophical understanding of the world, Plato dualized the real world in which phenomenon and essence were integrated, that is, he constructed an ideal world outside the perceptual world. Ideas are the basis of perceptual things, and perceptual things are the derivatives of ideas. Plato's theory of ideas, as an objective idealism system, is completely absurd; As a development link in the history of western philosophy, idealism is meaningful to deepen the discussion of individual and universality, sensibility and rationality, phenomenon and essence.
Aristotle was a master of ancient Greek philosophy. Ancient Greek philosophy started from Humily DuDu School, and put forward and discussed the origin of all things. According to Aristotle's understanding, the so-called "primitive" or "original" means that everything is made up of it, produced by it first, and finally returned to it. Before Aristotle, there were obviously two opposing views on what was the origin of all things: one thought that the origin was the material element of things, from water, fire, earth and gas to "root", "seed" and atom; The other holds that origin is a universal category and principle, such as Pythagoras' number, the existence of Elias school and Plato's idea. On the basis of summarizing the early Greek natural philosophy, Aristotle turned the problem of primitivism into the problem of ontology, which is a progress in philosophical thought.
From the theory of origin to ontology, it embodies the deepening of human philosophical feelings of seeking the foundation of living and living. The so-called ontology is the ultimate existence. Aristotle called the study of "existence as existence" or the study of existence itself "the first philosophy", that is, metaphysics. In Aristotle's view, philosophy is different from other sciences not only in the research object, but also in the research purpose. Learning philosophy is to pursue wisdom, not practicality. Philosophy is the only "free learning" in the world. Aristotle believes that philosophy studies "existence as existence", which is the most universal and universal existence without any specific "existence" characteristics. Aristotle divides this most general existence into two categories: one is the "existence" of movement and the time, space, finiteness and infinity related to movement, which are the research objects of natural philosophy; One is the unchangeable "being", which is the research object of the first philosophy.
Physics is Aristotle's most important natural philosophy work. Aristotle's physics is physics in a broad sense, and its original meaning is nature. He defined "nature" as "the origin of movement and change" in physics [13]. Nature is moving and changing, and the root of movement and change is nature itself. In order to highlight the position of natural philosophy, Aristotle divided "things that exist" into two categories: one is things that exist because of nature; One is something that "exists for other reasons" [14]. The former things, such as all kinds of animals, plants and simple objects (earth, fire, gas and water), are characterized in that everything in this category has a source of movement and stillness within itself; The latter is man-made things, such as beds, clothes, houses, etc. It is characterized by obvious traces of human activities, so the driving force for change is not within itself. Judging from the distinction between natural things and all things related to people, in Aristotle's philosophy, "nature" can also be said to be the inherent self-movement ability and inherent essential characteristics of all things in the universe.