(natura, φύσις) signifies by its etymology the origin and production of existences. But usage has assigned to the term a great number of significations, which are not always clearly distinguished. They are all referable to two classes, however, according as they apply to the nature of some particular thing, or to nature in general. 1. When the word is applied to some particular existence, it is used in three distinct senses:—1. As descriptive of the essential qualities of any concrete existence, as distinguished from those qualities which are accidental. 2. As descriptive of the essential qualities of a given genus or species, and by which it is distinguished from every other genus or species. 3. As descriptive of the essence and attributes of the absolute, or of the essence of abstract existences,—as when we speak of the nature of Deity, the nature of the Divine wisdom, the nature of duty, the nature of such and such a law. II. When the word is applied to nature in general, it is employed in four distinct significations:—1. As a collective name for all the forces exerted by man beyond the region of reflective intelligence and will. It is in this sense that nature is distinguished from art in the development of the human faculties, and in the power put forth by man on the animal, vegetable, and inorganic kingdoms. 2. As a collective term for all corporeal existences as distinguished from incorporeal. It is in this sense that those sciences which deal with material phenomena are termed natural sciences. 3. As a term used to designate the permanent but inexplicable fact of the constant production, destruction, and general variability of the phenomena of the universe. Sometimes this fact has been personified and metaphorically endowed with intelligence, volition, desire, and even moral qualities; and philosophers have not unfrequently been the dupes of this figure of speech. Nature, which in this sense was the expression of a fact to be explained, thus became, in the hands of not a few, the general explanation of all the special phenomena connected with this universal fact. 4. As the name given to that productive, destructive, or modifying force, which, whether considered as one or many, created or uncreated, possessing self-intelligence or the blind work of a creating intelligence, is the cause of all the changes which take place in the universe beyond the sphere of the volition of men and animals. The laws of this force are the principal objects of the physical sciences; the objects of natural history are the results of the operations of those laws.