This scholastic theory of law finds eloquent expression in the writings of Hooker in the sixteenth century. “His commanding those things to be which are, and to be in such sort as they are, to keep that tenure and course which they do, importeth the establishment of nature’s law.... Since the time that God did first proclaim the edicts of his law upon it, heaven and earth have hearkened unto his voice, and their labour hath been to do his will.... See we not plainly that the obedience of creatures unto the law of nature is the stay of the whole world.”[[43]] “Of law there can be no less acknowledged, than that her seat is the bosom of God, her voice the harmony of the world, all things in heaven and earth do her homage.”[[44]]
The modern use of the term law, in the sense of physical or natural law, to indicate the uniformities of nature, is directly derived from this scholastic theory of the lex aeterna; but the theological conception of divine legislation on which it was originally based is now eliminated or disregarded. The relation between the physical law of inanimate nature and the moral or civil laws by which men are ruled has been reduced accordingly to one of remote analogy.
§ 16. Natural or Moral Law.
By natural or moral law is meant the principles of natural right and wrong—the principles of natural justice, if we use the term justice in its widest sense to include all forms of rightful action. Right or justice is of two kinds, distinguished as natural and positive. Natural justice is justice as it is in deed and in truth—in its perfect idea. Positive justice is justice as it is conceived, recognised, and expressed, more or less incompletely and inaccurately, by the civil or some other form of human and positive law. Just as positive law, therefore, is the expression of positive justice, so philosophers have recognised a natural law, which is the expression of natural justice.
This distinction between natural and positive justice, together with the corresponding and derivative distinction between natural and positive law, comes to us from Greek philosophy. Natural justice is φυσικὸν δίκαιον; positive justice is νομικὸν δίκαιον; and the natural law which expresses the principles of natural justice is φυσικὸς νόμος. When Greek philosophy passed from Athens to Rome, φυσικὸν δίκαιον appeared there as justitia naturalis and φυσικὸς νόμος as lex naturae or jus naturale.
This natural law was conceived by the Greeks as a body of imperative rules imposed upon mankind by Nature, the personified universe. The Stoics, more particularly, thought of Nature or the Universe as a living organism, of which the material world was the body, and of which the Deity or the Universal Reason was the pervading, animating, and governing soul; and natural law was the rule of conduct laid down by this Universal Reason for the direction of mankind.
Natural law has received many other names expressive of its divers qualities and aspects. It is Divine Law (jus divinum)—the command of God imposed upon men—this aspect of it being recognised in the pantheism of the Stoics, and coming into the forefront of the conception, so soon as natural law obtained a place in the philosophical system of Christian writers. Natural law is also the Law of Reason, as being established by that Reason by which the world is governed, and also as being addressed to and perceived by the rational nature of man. It is also the Unwritten Law (jus non scriptum), as being written not on brazen tablets or on pillars of stone, but solely by the finger of nature in the hearts of men. It is also the Universal or Common Law (κοινος νόμος, jus commune, jus gentium), as being of universal validity, the same in all places and binding on all peoples, and not one thing at Athens and another at Rome, as are the civil laws of states (ἴδιος νόμος, jus civile). It is also the Eternal Law (lex aeterna), as having existed from the commencement of the world, uncreated and immutable. Lastly, in modern times we find it termed the Moral Law, as being the expression of the principles of morality.
The term natural law, in the sense with which we are here concerned, is now fallen almost wholly out of use. We speak of the principles of natural justice, or of the rules of natural morality, but seldom of the law of nature, and for this departure from the established usage of ancient and medieval speech there are at least two reasons. The first is that the term natural law has become equivocal; for it is now used to signify physical law—the expression of the uniformities of nature. The second is that the term law, as applied to the principles of natural justice, brings with it certain misleading associations—suggestions of command, imposition, external authority, legislation—which are not in harmony with the moral philosophy of the present day.
The following quotations illustrate sufficiently the ancient and medieval conceptions of the law of nature:—
Aristotle.—“Law is either universal (κοινος νόμος) or special (ἴδιος νόμος). Special law consists of the written enactments by which men are governed. The universal law consists of those unwritten rules which are recognised among all men.”[[45]] “Right and wrong have been defined by reference to two kinds of law.... Special law is that which is established by each people for itself.... The universal law is that which is conformable merely to Nature.”[[46]]