Nature etymologically (Latin natura from nasci, to be born, like the corresponding Greek phusis from phuein, to bring forth) has reference to the production of things, and hence generally includes in its connotation the ideas of energy and activity. It will be convenient to reduce to two classes the various meanings of the term nature according as it applies to the natures of individual beings or to nature in general.
I. In an individual being, especially if its constitutive elements and its activities are manifold and complex, the term nature is sometimes applied to the collection of distinctive features, original or acquired, by which such an individual is characterized and distinguished from others. Thus it may be said it is the nature of one man to be taller, stronger, more intelligent, or more sociable than another. This meaning, however, is superficial; in philosophical terminology and even in ordinary language, nature refers to something deeper and more fundamental. These features are manifestations of a man's nature; they are not his nature. Nature properly signifies that which is primitive and original, or, according to etymology, that which a thing is at birth, as opposed to that which is acquired or added from external sources. But the line that divides the natural from the artificial cannot be drawn with precision. Inorganic beings never change except under the influence of external agencies, and in the same circumstances, their mode of activity is uniform and constant. Organisms present a greater complexity of structure, power of adaptation, and variety of function. For their development out of a primitive germ they require the cooperation of many external factors, yet they have within themselves the principle of activity by which external substances are elaborated and assimilated. In any being the changes due to necessary causes are called natural, whereas those produced by intentional human activity are called artificial. But it is clear that art supposes nature and is but a special adaptation of natural aptitudes, capacities, or activities for certain aesthetic or useful purposes. Stars, rivers, forests, are works of nature; parks, canals, gardens, and machines are works of art. If necessary conditions are realized, where the seed falls a plant will grow naturally. But the seed may be placed purposely amid certain surroundings, the growth of the plant may be hastened, its shape altered, and, in general, the result to be expected from natural activities may be modified. By training the aptitudes of an animal are utilized and its instincts adapted for specific ends. In such cases the final result is more or less natural or artificial according to the mode and amount of human intervention.
In scholastic philosophy, nature, essence, and substance are closely related terms. Both essence and substance imply a static point of view and refer to constituents or mode of existence, while nature implies a dynamic point of view and refers to innate tendencies. Moreover, substance is opposed to accidents, whereas we may speak of the nature and essence not only of substances but also of accidents like color, sound, intelligence, and of abstract ideal: like virtue or duty. But when applied to the same substantial being, the terms substance, essence, and nature in reality stand only for different aspects of the same thing, and the distinction between them is a mental one. Substance denotes the thing as requiring no support, but as being itself the necessary support of accidents; essence properly denotes the intrinsic constitutive elements by which a thing is what it is and is distinguished from every other; nature denotes the substance or essence considered as the source of activities. "Nature properly speaking is the essence (or substance) of things which have in themselves as such a principle of activity (Aristotle, "Metaphysics", 1015a, 13). By a process of abstraction the mind arises from individual and concrete natures to those of species and genera.
A few special remarks must be added concerning human nature. This expression may mean something concrete, more or less different in various individuals, or more generally something common to all men, i.e., the abstract human nature by which mankind as a whole is distinguished from other classes of living beings. In both cases it is conceived as including primitive and fundamental characteristics, and as referring to the source of all activities. Hence nature, as the internal principle of action, is opposed in the first place to violence and coercion which are external principles of action and prevent the normal play of human faculties. It is opposed also, but less strictly, to education and culture which at times may be the checking of natural tendencies, at times also their development and perfection. Education, physical and mental, is not a primitive endowment; it must be acquired and is built upon nature as on its foundation. In this sense habit has been termed a second nature. But although education is due largely to external causes and influences acting on the mind and the organism, from another point of view it is also the unfolding of innate aptitudes, and hence partly natural.
As between nature in general and art, so between human nature and education there is no clear dividing line. Natural is also frequently contrasted with conventional; language, style, gestures, expressions of feelings, etc., are called more or less natural. This opposition becomes more acute in the theories of Hobbes and Rousseau who lay stress on the antithesis between the primitive or natural state of man and the present social condition due to the contract by which men agreed to surrender their rights into the hands of the common authority.
From the theological point of view the distinctions between nature and person and between the natural and the supernatural orders are of primary importance. The former arose from the dogma of the Trinity, i.e., of one Divine Nature in three persons, and chiefly from that of the Incarnation i.e., of the two Natures, Divine and human, in the one Divine Person in Christ. The Human Nature in Christ is complete and perfect as nature, yet it lacks that which would make it a person, whether this is something negative, as Scotists hold, namely the mere fact that a nature is not assumed by a higher person, or, as Thomists assert, some positive reality distinct from nature and making it incommunicable.
The faculties of man are capable of development and perfection, and, no matter what external influences may be at work, this is but the unfolding of natural capacities. Even artificial productions are governed by the laws of nature, and, in man, natural activities, after they are perfected differ not in kind but only in degree, from those that are less developed. The supernatural order is above the exigencies and capacities of all human nature. It consists of an end to be reached, namely, the intuitive vision of God in heaven—not the mere discursive and imperfect knowledge which is acquired by the light of reason—and of the means to attain such an end, namely, a principle which must be added to natural faculties so as to uplift them and make them capable of knowing and reaching this higher destiny. More specifically it includes an enlightenment of the intellect by a positive revelation of God manifesting man's super-natural end and the conditions for obtaining it; it also implies for every individual the indispensable help of Divine grace both actual, by which God illumines and strengthens human faculties, and sanctifying, by which human nature is elevated to a higher mode of activity. Hence theologians oppose the state of pure nature in which God could have placed man, to the supernatural state to which in fact man was raised.
II. Nature is frequently taken for the totality of concrete natures and their laws. But here again a narrower and a broader meaning must be distinguished. Nature refers especially to the world of matter, in time and space, governed by blind and necessary laws, and thus excludes the mental world. Works of nature, opposed to works of art, result from physical causes, not from the actual adaptation by human intelligence. This signification is found in such expressions as natural history, natural philosophy, and in general, natural science, which deal only with the constitution, production, properties, and laws of material substances. Sometimes also nature is all-inclusive, embracing mind as well as matter; it is our whole world of experience, internal as well as external. And frequently nature is looked upon as a personified abstraction, as the one cause of whatever takes place in the universe, endowed with qualities, tendencies, efforts, and will, and with aims and purposes which it strives to realize.
The problems to which the philosophical study of nature has given rise are numerous. All however center around the question of the unity of nature: Can all the beings of the world be reduced to one common principle, and if so what is this principle? The first Greek philosophers, who were almost exclusively philosophers of nature, endeavored to find some primitive element out of which all things were made; air, water, fire, and earth were in turn or all together supposed to be this common principle. The problem has persisted through all ages and received many answers. Aristotle's primary matter, for instance, is of the same nature in all things; and today ether, or some other substance or energy is advocated by many as the common substratum of all material substances. After static unity, dynamic unity is looked for, that is, all the changes that take place in the universe are referred to the same principle. Dynamism (q.v.) admits forces of various kinds which, however, it tries to reduce to as small a number as possible, if not to only one form of energy manifesting itself in different ways. Mechanism (q.v.) holds that everything is explainable by the sole assumption of movement communicated from one substance to another. Teleological views give to final causes a greater importance, and look upon the ends of various beings as subordinated to the one end which the universe tends to realize.
If nature includes both mental and physical phenomena what are the relations between these two classes? On this point also the history of philosophy offers many attempts to substitute some form of Monism for the Dualism of mind and matter, by reducing mind to a special function of matter, or matter to a special appearance of mind, or both to a common substratum.
Finally, is nature as a whole self-sufficient, or does it require a transcendent ground as its cause and principle? Is the natura naturans one and the same with the natura naturata? By some these expressions are used in a pantheistic sense, the same substance underlies all phenomena; by others the natura naturans, as first cause, is held to be really distinct from the natura naturata, as effect. This is the question of the existence and nature of God and of his distinction from the world. Here the question of the possibility of miracles is suggested. If nature alone exists, and if all its changes are absolutely necessary, everything takes place according to a strict determinism. If, on the contrary, God exists as a transcendent, intelligent, and free cause of nature and its laws, not only nature in all its details depends ultimately on God's will, but its ordinary course may be suspended by a miraculous intervention of the First Cause. (See Arts; Naturalism; Supernatural; Grace)
C. A. DUBRAY