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them upon general notions of their own, supposed to be self-supporting, and whilst the contents of religious as well as of metaphysical systems are as boundless as the range of human imagination and desires, science, which is not less infinite than the world, and therefore than truth itself, always remains one and uniform. This, however, can only be admitted to apply to science so perfect, complete and exhaustive as to comprise the entire sum and system of knowledge, embracing every single appearance in the whole universe. Since, in such a case, every appearance would be exhibited in the chain of each of its causes and effects, every item of knowledge, too, would find its proper place in the relative order of its connections, and each would throw light on an endless series of antecedents and consequences. We ought, therefore, to be able to distinguish as many sciences as we do separate groups of phenomena and knowledge. But, in truth, the universe does not present the spectacle of separate disconnected threads of appearances. On the contrary, all our experience constantly points to their most intimate union and continuous connection; all co-existent factors are ever reacting upon each other, commingling in the production. of common results, and may be traced to a common origin. Every atom reflects in itself the actual state of every other part of the universe, and every change is evidence of the rule of the uniform law of nature.

The hypothesis of such a law derives therefore its origin not only from the psychological fact that we are prone to consider the outer world as a unity, by reason of comparing it with the unity of the mass of our individual consciousness, but it is also supported by the evidence of experience. For, in analyzing the multiplicity of appearances, we discover them to be cases of the application of laws, growing ever more general and decreasing in number and complexity. Besides, forces are found to be convertible and expressive of equivalents of each other, and the properties of the material elements themselves appear inter-dependent and present the possibility of being

enrolled in an ascending series, and, consequently, of being reducible to each other. Thus, the most satisfactory explanation of the material world seems to be conveyed by supposing it to be a mechanical totality, the effect of the concurrent operations of a single force, proceeding from an infinity of centres of power. The unity of perfect science corresponds, therefore, entirely with the unity of the universe.

Of course this assertion can be only supported by showing spiritual life to be also amenable to law, and to be in every respect unavoidably connected with the world of material appearances. That such is the case, we may infer from the experience that every single moment of spiritual life may be reduced to some change of sensation, and that every sensation is again accompanied by some material modification of the sensible organism as to some of its circumstances, whilst, on the other hand, some change of sensation always follows every material impression, although it be not always expressed in conscious perception. This experience does not necessarily lead to the doctrine of materialism, which supposes that material factors are transmuted into spiritual forces, and that the same transmutation also takes place conversely. Nay, such a supposition seems to be excluded by the principle of the persistence of force, at least according to our present capabilities of measurement, experience showing that every material change demands an equivalent quantity of force for its material cause.

Yet, since physical and mental experiences develop and grow more and more complex in strict parallelism to each other, it is undeniable that an intimate connection exists between the two groups of phenomena, and that mental life, arbitrary in the consciousness of the subject itself, is, when considered objectively, amenable to the uniform rule of law.

§ 5. But even allowing that the spiritual and material world were each subject to a different and separate class of laws, and that we were unable to entertain the

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hypothesis of a parallel course of causality permeating both a supposition which can hardly be conceived, if we consider the permanent connection and intimate interaction of impressions, sensations, ideas, wants, emotions and actions, which are never marred by a single exception, -we should, even in that case, be merely obliged to recognize two sciences, connected indeed with each other, yet irreducible to any common higher law, each relating purely to phenomena, or rather to relations subsisting between appearances, and each being conclusive as to the laws of causation within its own separate province.

The notion of science itself excludes however, under all circumstances, the doctrine of metaphysical free-will which represents the human will as being absolutely arbitrary, and, consequently, as an independent, self-acting source of mental, and therefore indirectly, of material, force. This doctrine is opposed to the uniform order of nature, that most general and most indispensable fundamental principle of science, the negation of which would be subversive both of the possibility of the conservation of energy, and of the idea of expediency. Uniformity of causality forms the antecedent to expediency; for, in pointing out anything as expedient, it means nothing unless we presuppose causation, and attribute certain consequences to certain antecedents. Human action, therefore is, if subjectively expedient, objectively necessarily subservient to the law of causality, and it is under this aspect alone that it may be regarded as an object of science. If, nevertheless, attempts have been made at various times to construct a moral or social science of a different character, accepting metaphysical free-will for a starting point, such paradoxical efforts may be accounted for by the fact that human laws are neither natural laws nor scientific truths which permit of no exception, but, being simply the commands of finite knowledge and power, and not invariably in accord with expediency, or if expedient, not being always recognized as such, the individual may or may not obey them, and, as a consequence,

the apparently arbitrary attitude of the human will in confronting these injunctions is wrongly generalized by being transferred to a different object with a different metaphysical meaning.*

§ 6. Theology and metaphysics have, however, in this respect, trespassed on the domain of science and not alone for the above reason. Owing to the finite condition of human consciousness, perfect, exhaustive science, embracing the plenitude of the appearances of the universe, so infinite in number, and becoming thus homogeneous and uniform in reality, is impossible, and, since we cannot ever hope to know the entire mass of phenomena, but only fewer or more of them, our science also must needs remain fragmentary and incomplete. As a consequence, every notion of ours is imperfect, owing to our inability to enumerate every one of its relations, antecedents and consequences; besides, separate groups of knowledge, initiating diverse branches of science are classified, because we know the laws of the relations of appearances within their limits more thoroughly than we do those of their connection with phenomena belonging to other branches.

The universe is refracted within the human mind, like rays of light passing through a prism, and is there broken up into groups of appearances, each varying in hue; and, blind to the delicate shades of transition between them, we are only able to conceive the original light approximately by a synthesis of these colours. Hence, we are unable accurately to determine the limits of each department of science, or to point out with precision the laws with which any particular science begins and ends. The chain of causality extends beyond finite limits. Consequently, the fundamental principles of every group of

*It is assumed in the first place that Divine law identified with natural law resembles human law. Starting with this assumption, the breach of Divine law is considered the foundation of evil. The existence of evil is then placed in antagonism to Divine omnipotence and goodness, and thus results an irreconcilable contradiction, which at last is explained away by the doctrine of absolute free-will.

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science lie beyond its proper boundaries, in part amongst the results of some other previous groups, in so far as any causal connection traversing both groups may have been ascertained, and in part do not yet rise to the dignity of science, being incapable of verification, and being thus mere hypotheses, that is, notions accepted provisionally as true, in hope of their possible explanation or ultimate verification.

The mind not scientifically disciplined is often apt to overlook the necessity of verifying such suppositions, either because, from being used to them, it looks upon them as natural and a matter of course, or because, not being cognizant of the conditions under which they might be analyzed, and doubting the possibility of accomplishing this, it impatiently accepts its own notions as absolute, and sometimes even regards the inconceivable as eternally valid, and its investigation as a sacrilege. In this manner, the separate and special branches of science, deduced from theological or metaphysical principles, originate. As regards the question, however, how a system built up upon notions antagonistic to science can contain real and actual knowledge, we must reflect that partly these notions themselves, and partly, too, the conclusions derived from them, embody amongst their elements, whether inadvertently or fraudulently, some results of observation, and, moreover, that they always contain that concomitant idea of the uniformity of causality ineradicable from all thought, the latter itself resting upon experience. But as science progresses, all hypotheses become more and more severely analyzed, and as they decrease, they constantly grow more simple. Thus both metaphysics and faith recede step by step from the realm of knowledge usurped by them without due title.

Every new discovery, every new perfection, imparts to us a fuller power of vision, enabling us to pursue further the chain of causality into regions to which hitherto final expediency, the Divine will, or an abstract formal idea alone seemed to have afforded a clue.