Nature has two inter-related meanings in philosophy and natural philosophy. On the one hand, it means the set of all things which are natural, or subject to the normal working of the laws of nature. On the other hand, it means the essential properties and causes of individual things.
How to understand the meaning and significance of nature has been a consistent theme of discussion within the history of Western Civilization, in the philosophical fields of metaphysics and epistemology, as well as in theology and science. The study of natural things and the regular laws which seem to govern them, as opposed to discussion about what it means to be natural, is the area of natural science.
The word "nature" derives from Latin nātūra, a philosophical term derived from the verb for birth, which was used as a translation for the earlier (pre-Socratic) Greek term phusis, derived from the verb for natural growth. Already in classical times, philosophical use of these words combined two related meanings which have in common that they refer to the way in which things happen by themselves, "naturally", without "interference" from human deliberation, divine intervention, or anything outside what is considered normal for the natural things being considered.
Understandings of nature depend on the subject and age of the work where they appear. For example, Aristotle's explanation of natural properties differs from what is meant by natural properties in modern philosophical and scientific works, which can also differ from other scientific and conventional usage.
Classical nature and Aristotelian metaphysics
The Physics (from ta phusika "the natural [things]") is Aristotle's principal work on nature. In Physics II.1, Aristotle defines a nature as "a source or cause of being moved and of being at rest in that to which it belongs primarily".Aristotle Physics 192b21 In other words, a nature is the principle within a natural raw material that is the source of tendencies to change or rest in a particular way unless stopped. For example, a rock would fall unless stopped. Natural things stand in contrast to artifacts, which are formed by human artifice, not because of an innate tendency. (The raw materials of a bed have no tendency to become a bed.) In terms of Aristotle's theory of four causes, the word natural is applied both to the innate potential of matter cause and the forms which the matter tends to become naturally.Aristotle Physics 193b21
According to Leo Strauss,"Progress or Return" in An Introduction to Political Philosophy: Ten Essays by Leo Strauss. (Expanded version of Political Philosophy: Six Essays by Leo Strauss, 1975.) Ed. Hilail Gilden. Detroit: Wayne State UP, 1989. the beginning of Western philosophy involved the "discovery or invention of nature". In contrast, the "pre-philosophical equivalent of nature" was supplied by "such notions as 'custom' or 'ways'". In ancient Greek philosophy on the other hand, Nature or natures are ways that are "really universal" "in all times and places". This in turn presupposes one can "find one's bearings in the cosmos" "on the basis of inquiry", but not for example on the basis of human customs such as religions or laws. To put this "discovery or invention" into the traditional terminology, what is "by nature" is contrasted to what is "by convention". This understanding of nature as something contrasted with human conventions remains a strong tradition in modern Western thinking. Science, according to Strauss' commentary of Western history is the contemplation of nature, while technology was or is an attempt to imitate it.Strauss and Cropsey eds. History of Political Philosophy, Third edition, p.209.
Going further, the philosophical concept of nature or natures as a special type of causation - for example that the way particular humans are is partly caused by something called "human nature" is an essential step towards Aristotle's teaching concerning causation, which became standard in all Western philosophy until the arrival of modern science.
Whether it was intended or not, Aristotle's inquiries into this subject were long felt to have resolved the discussion about nature in favor of one solution. In this account, there are four different types of cause: The material cause is the "raw material" - the matter which undergoes change. One of the causes of a statue being what it is might be that it is bronze. All meanings of the word nature encompass this simple meaning. The efficient cause is the motion of another thing, which makes a thing change, for example a chisel hitting a rock causes a chip to break off. This is the way which the matter is forming into a form so that it become substance like what Aristotle said that a substance must have a form and matter in order to call it substance. This is the motion of changing a single being into two. This is the most obvious way in which cause and effect works, as in the descriptions of modern science. But according to Aristotle, this does not yet explain that of which the motion is, and we must "apply ourselves to the question whether there is any other cause per se besides matter".Metaphysics 995b, translated by Hugh Tredennick. Greek: μάλιστα δὲ ζητητέον καὶ πραγματευτέον πότερον ἔστι τι παρὰ τὴν ὕλην αἴτιον καθ᾽ αὑτὸ ἢ οὔ The formal cause is the form or idea which serves as a template towards which things develop - for example following an approach based upon Aristotle we could say that a child develops in a way partly determined by a thing called "human nature". Here, nature is a cause. The final cause is the aim towards which something is directed. For example, a human aims at something perceived to be good, as Aristotle says in the opening lines of the Nicomachean Ethics.
The formal and final cause are an essential part of Aristotle's "Metaphysics" - his attempt to go beyond nature and explain nature itself. In practice they imply a human-like consciousness involved in the causation of all things, even things which are not man-made. Nature itself is attributed with having aims.As for example Aristotle Politics 1252b.1: "Thus the female and the slave are by nature distinct (for nature makes nothing as the cutlers make the Delphic knife, in a niggardly way, but one thing for one purpose; for so each tool will be turned out in the finest perfection, if it serves not many uses but one"
The artificial, like the conventional therefore, is within this branch of Western thought, traditionally contrasted with the natural. Technology was contrasted with science, as mentioned above. And another essential aspect to this understanding of causation was the distinction between the accidental properties of a thing and the substance - another distinction which has lost favor in the modern era, after having long been widely accepted in medieval Europe.
To describe it another way, Aristotle treated organisms and other natural wholes as existing at a higher level than mere matter in motion. Aristotle's argument for formal and final causes is related to a doctrine about how it is possible that people know things: "If nothing exists apart from individual things, nothing will be intelligible; everything will be sensible, and there will be no knowledge of anything—unless it be maintained that sense-perception is knowledge".Metaphysics 999b, translated by Hugh Tredennick. Greek: εἰ μὲν οὖν μηδέν ἐστι παρὰ τὰ καθ᾽ ἕκαστα, οὐθὲν ἂν εἴη νοητὸν ἀλλὰ πάντα αἰσθητὰ καὶ ἐπιστήμη οὐδενός, εἰ μή τις εἶναι λέγει τὴν αἴσθησιν ἐπιστήμην. Those philosophers who disagree with this reasoning therefore also see knowledge differently from Aristotle.
Aristotle then, described nature or natures as follows, in a way quite different from modern science:
It has been argued, as will be explained below, that this type of theory represented an oversimplifying diversion from the debates within Classical philosophy, possibly even that Aristotle saw it as a simplification or summary of the debates himself. But in any case the theory of the four causes became a standard part of any advanced education in the Middle Ages.
In Eastern philosophy
Indian philosophy Jain philosophy attempts to explain the rationale of being and existence, the nature of the Universe and its constituents, the nature of bondage and the means to achieve liberation. Jainism strongly upholds the individualistic nature of soul and personal responsibility for one's decisions; and that self-reliance and individual efforts alone are responsible for one's liberation. p. 220
Ajñana was a Śramaṇa school of radical Indian skepticism and a rival of early Buddhism and Jainism. They held that it was impossible to obtain knowledge of metaphysical nature or ascertain the truth value of philosophical propositions;Jayatilleke, K.N. (1963). Early Buddhist Theory of Knowledge (PDF) (1st ed.). London: George Allen & Unwin Ltd. pp. 112–113. and even if knowledge was possible, it was useless and disadvantageous for final salvation. They were seen as sophists who specialized in refutation without propagating any positive doctrine of their own. Jayarāśi Bhaṭṭa (fl. c. 800), author of the skeptical work entitled Tattvopaplavasiṃha ("The Lion that Devours All Categories"/"The Upsetting of All Principles"), has been seen as an important Ajñana philosopher.Salunkhe, AH (2009). Astikshiromani Charvaka (in Marathi). Satara: Lokayat Prakashan. p. 36.
In the Chandogya Upanishad, Aruni asks metaphysical questions concerning the nature of reality and truth, observes constant change, and asks if there is something that is eternal and unchanging. From these questions, embedded in a dialogue with his son, he presents the concept of Ātman (soul, Self) and universal Self.Ben-Ami Scharfstein (1998), A comparative history of world philosophy: from the Upanishads to Kant, Albany: State University of New York Press, pp. 9-11
The Ashtavakra Gita, credited to Aṣṭāvakra, examines the metaphysical nature of existence and the meaning of individual freedom, presenting its thesis that there is only one Supreme Reality (Brahman), the entirety of universe is oneness and manifestation of this reality, everything is interconnected, all Self (Atman, soul) are part of that one, and that individual freedom is not the end point but a given, a starting point, innate.
The first book of Yoga Vasistha, attributed to Valmiki, presents Rama's frustration with the nature of life, human suffering and disdain for the world. The second describes, through the character of Rama, the desire for liberation and the nature of those who seek such liberation. The fourth describes the nature of world and many non-dualism ideas with numerous stories. It emphasizes free will and human creative power.Surendranath Dasgupta, A History of Indian Philosophy, Volume 2, Cambridge University Press, , pages 252-253
Ancient Mīmāṃsā's central concern was epistemology (pramana), that is what are the reliable means to knowledge. It debated not only "how does man ever learn or know, whatever he knows", but also whether the nature of all knowledge is inherently circular, whether those such as foundationalists who critique the validity of any "justified beliefs" and knowledge system make flawed presumptions of the very premises they critique, and how to correctly interpret and avoid incorrectly interpreting dharma texts such as the Vedas. To Mīmānsā scholars, the nature of non-empirical knowledge and human means to it are such that one can never demonstrate certainty, one can only falsify knowledge claims, in some cases.