hand is the great champion of indeterminism. Upon his view the intellect must always be subordinate to the will, and to the will belongs the power of complete self-determination. Morality in effect—to such an extreme position is he driven in his opposition to the Thomists—becomes the arbitrary creation of the Divine Will and in no sense depends for its authority upon rational principles or is a form of knowledge.
The modern treatment of the problem from Descartes, Hobbes, Spinoza and Leibnitz down to Kant is too much inwoven into Hobbes and Descartes. the metaphysical systems of individual great philosophers to afford the possibility of detailed treatment in the present article. Reference should be made either to the individual philosophers themselves or to articles on metaphysics or on ethics. Hobbes is the great exponent of materialistic determinism. Ideals and volitions are upon his view ultimately movements of the brain. Will is identified with appetite or fear, the causes of which are to be found only in the external world. Descartes advocates a kind of freedom which is apparently consistent with forms both of determinism and indeterminism. He explains the possibility of error on the ground that the mind possesses the liberum arbitrium indifferentiae and can always refuse to affirm the truth of a conclusion drawn from premises which are not self-evident. And even when the presentations before the mind are so clear that assent to their truth cannot be refused, the possibility of assenting still rests with the will, which can refuse to attend to any presentation, or can refuse assent with the sole motive of proving its freedom. Spinoza is a convinced determinist regarding the will as necessarily determined by ideas. Extension, i.e. the spatial world, and the world of Spinoza and Leibnitz. consciousness are alike attributes of the one substance which can only be called free in the sense of being determined by nothing but itself. Freedom in the moral sphere consists simply in the control of the passions by reason. Leibnitz retains this attenuated belief in moral freedom and combines with it a belief in the spontaneity of moral agents in the sense that they possess the power of acting and need no other principle of action save the laws of their own natures. But inasmuch as the agreement between the acts of Leibnitz's monads is due to a divine pre-established harmony, and the theoretical contingency which in the abstract, i.e. as logically possible, can be predicated of their acts, is in practice non-existent, Leibnitz is in effect a determinist.
Locke's treatment of the problem is in some respects more interesting than the theories of other English philosophers Locke and Hume. of his school. Freedom, according to Locke, belongs to the man, not to the will. If we will at all we are to that extent free, i.e. our actions express our purposes. If, on the other hand, we press Leibnitz's objection, i.e. that such an argument is no answer to the question whether an act of will can be free in the sense that it is not determined by reasons presented by the understanding, Locke replies that the will is in effect determined by the uneasiness of desire, i.e. by the desire to avoid pain. Hume's doctrine follows logically from his theory as to the nature of causality. If our belief in necessary connexion in the physical world is in reality an illusion, it follows that the opposition between freedom and necessity will be illusory also. On the other hand if our belief in the necessity of causal connexion is the result of custom, to custom will be due also the belief in a necessity governing human actions observable everywhere in men's ordinary opinions and practice. Contrasted with this belief in necessity the supposition we have of freedom is illusory, and, if extended so as to involve a belief that men's actions do not proceed from character or habitual disposition, immoral.
Kant's theory of freedom is, perhaps, the most characteristic doctrine of his system of ethics. Distinguishing between two Kant. worlds, the sensuous and the intelligible, the phenomenal and the noumenal, Kant allows no freedom to the natural will determined by the succession of motives, desires and appetites which form the empirical and sensuous self. But in contrast with the phenomenal world governed by empirical laws Kant sets the noumenal and intelligible world in which by a timeless act of will man is free to accept the moral command of an unconditional imperative for no reason other than its own rational necessity as the deliverance of his highest nature. The difficulties of the Kantian system are mainly to be looked for in his account of the relation between the phenomenal and noumenal world.
In more recent times the controversy has been concerned either with the attempted proof of determinism by the Modern materialism. advocates of psychological Hedonism, an attempt which at the present time is generally admitted to have failed; or with the new biological knowledge concerning the influence of heredity and environment in its bearing upon the development of character and the possibility of freedom. The great advance of biological knowledge in recent times though it has in no sense created a new problem (men have always been aware of the importance of racial or hereditary physical qualities in their influence upon human conduct) has certainly rendered the existence of complete individual freedom (in the sense in which it was advocated by older libertarians) in the highest degree unlikely. The advocates of freedom are content in the present day to postulate a relative power of influencing conduct, e.g. a power of controlling inherited temperament or subduing natural passion. Such a relative freedom, indeed, taking into account the admitted inviolability of natural laws, was from the very beginning all that they could claim.
But it was inevitable that the enormous advances made by the physical and other sciences in modern times should bring with them a reasoned attempt to bring the phenomena of consciousness within the sphere controlled by physical laws and natural necessity. There will never perhaps in any period of the world's history be wanting advocates of materialism, who find in the sensible the only reality. But the materialism of modern times is more subtle than that of Hobbes. And the determinism of modern science no longer consists in a crude denial of the reality of conscious processes, or an attempt to explain them as only a sublimated form of matter and its movements; it is content to admit the relative independence of the world of consciousness, while it maintains that laws and hypotheses sufficient to explain material processes may be extended to and will be discovered to be valid of the changing sequences of conscious states of mind. Moreover, much of the apparent cogency of modern scientific determinist arguments has been derived from the unguarded admissions or timorous acquiescence of their opponents. It is not enough merely to repel the incursions of physiological science, armed with hypotheses and theories valid enough in their own sphere, upon the domain of consciousness. If the attack is to be finally repulsed it will be imperatively necessary for the libertarian to maintain that no full explanation of the physical universe can ever gain assent which does not take account of the reality and influence within the material world of human power of initiative and freedom. Of this necessity there is a growing consciousness in recent years, and no more notable exposition of it has been published than is contained in James Ward's Naturalism and Agnosticism. Nor is there any lack of evidence of a growing dissatisfaction on the part of many physiologists with the complacent assumption that the methods of physical science, and particularly the conception of causal activity common to the sciences which study inorganic nature, can be transferred without further criticism to the examination of life and mind. Meanwhile the scientific onslaught upon the libertarian position has been directed from two chief quarters. It has been maintained, on the one hand, that any theory which presupposes a direct correspondence between the molecular movements of the brain, and the states of consciousness which accompany them must make the freedom of the will impossible. On the other hand it is asserted that quite apart from any particular view as to the relation between mind and body the existence of the freedom of the will is necessarily incompatible with the principle of the conservation of energy and is therefore in direct contradiction to
