any exact knowledge-i.e., science—so long as material properties are not reached? The materialist answers all these questions in the negative. And, at the same time, he contends that the theistic mode of accounting for the universe by the creative fiat of an Eternal Being is particularly unintelligible. Such a supposition seems to him to be one which cannot, properly speaking, be realised in thought at all. A man may verbally express it, and even fancy that he believes it, yet it is in itself essentially inconceivable.

From preliminary considerations like the foregoing, the materialist may proceed to what is strictly his argument, which still remains to be stated. It consists in maintaining that the facts. of nature do not in any case demand for their explanation a principle or principles distinct from matter. The properties of matter are the sole, the direct, and the immediate objects of the senses. They confront the mind from the earliest dawn of consciousness, and are apprehended by it long before self-reflection is elicited. Touch, taste, sight, hearing, and smell, all converge on matter, and constrain us to commence with it. Before we abandon it and its properties, the necessity of having recourse to a distinct substance with distinct properties must be clearly made out. In the inorganic world no such necessity arises. Yet it is a world rich in differences, presenting a vast

variety of constituents and forces, of stages and processes, of colours, sounds, savours, and odours. The objects of one sense are quite unlike those of another, and light, heat, electricity, and magnetism appear to be entirely distinct. But examination discovers everywhere an essential sameness. It was the glory of the atomic or materialistic philosophy of ancient Greece to have recognised that the diversity of things was only secondary; that underneath the phenomenal variety was real identity; that all qualitative distinctions might be resolved into quantitative distinctions. This truth has not only been fully confirmed in modern times, but has been brilliantly supplemented and completed by the great discovery of the correlation of forces. Light, heat, electricity, magnetism, chemical affinity, and mechanical motion, have been ascertained to be convertible. Any one of them may be transformed into any other. They are but modes of the movements which take place among the molecules of matter. They are but the metamorphoses of a common force, which is unchangeable in amount although variable in quality.

Does the anti-materialist argue that, however the case may stand with the inorganic world, organisation cannot be conceived of as a product of molecular combinations and mechanical forces? Does he contend that there is a chasm or gulf between inorganic and organic nature, and that

materialism fails to bridge over the distance between the one region and the other? It may be replied that this is an argument based not on knowledge but on ignorance, and addressed not to knowledge but to ignorance. Because we do not know that purely physical forces can construct a living cell as we know that they can build up a crystal, we infer that they cannot do the former. But logic warrants no such inference. A solution of continuity, a chasm, in knowledge is no proof that there is a solution of continuity or chasm in nature. Ignorance cannot be legitimately reasoned from as if it were knowledge.

Further, Is not the gap in science being gradually filled up? Is not knowledge as it advances making it apparent that there is no gap in nature at the point indicated? In the light of recent science we cannot but vividly realise that matter is capable of transformations so diversified and wonderful that we must be very cautious before we venture to assign limits to its powers of adaptation, change, and efficiency. The same particle of it may in succession be a constituent of a drop of dew, of an invisible vapour, of a crystal of snow, of a mineral, of the stem, sap, flower, or fruit of a plant, and of the flesh, blood, bone, or brain of man, performing necessarily very different functions in the several instances. Crystallisation is a process scarcely less marvellous in itself and in its

results than growth. Why are we not to believe that in the latter process no less than in the former every molecule is placed in its position not by any external power, whether creative mind or vital principle, but by attractions and repulsions due to the natures of the molecules themselves? If matter can display in special circumstances the structural powers exhibited in crystallisation, why may it not in other, perhaps more complex circumstances, manifest the organic powers witnessed in vegetable and animal growth?

It was until recently supposed that there was a chasm which could not be bridged over between the very chemistry of inorganic and organic bodies, and that no animal substances could be compounded by the chemist. This doctrine is now overthrown. The supposed break in nature which was regarded as indicating the presence and intervention of a distinct principle in organised structures is now found to have been but a blank in our knowledge. "Not many years since," says Mr Spencer, "it was held as certain that the chemical compounds distinguished as organic could not be formed artificially. Now, more than a thousand organic compounds have been formed artificially. Chemists have discovered the art of building them up from the simpler to the more complex; and do not doubt that they will eventually produce the most complex."

That the matter of organic bodies is the same as that of inorganic objects has, of course, a very important bearing on the question whether or not vitality is resolvable into the mechanical properties and chemical processes of matter. What that bearing is I shall leave it to Professor Huxley to state. Treating of the "Physical Basis of Life," he writes: "Plants are the accumulators of the power which animals distribute and dispense. But it will be observed that the existence of the matter of life depends on the pre-existence of certain compounds—namely, carbonic acid, water, and ammonia. Withdraw any one of these three from the world, and all vital phenomena come to an end. They are related to the protoplasm of the plant as the protoplasm of the plant is to that of the animal. Carbon, hydrogen, oxygen, and nitrogen are all lifeless bodies. Of these, carbon and oxygen unite in certain proportions, and under certain conditions, to give rise to carbonic acid; hydrogen and oxygen produce water; nitrogen and hydrogen give rise to ammonia. These new compounds, like the elementary bodies of which they are composed, are lifeless. But when they are brought together under certain conditions, they give rise to the still more complex body, protoplasm, and this protoplasm exhibits the phenomena of life. I see no break in this series of steps in molecular complication, and I am unable