Part 7

The doctrine that evolution consists in nothing but movements in space, amounts to the assertion that we know nothing about things and men except that they move. In point of fact, we know a good deal more. We know that men think, and that the movement of thought is not a movement in space. We know that the vibrations of the ether are movements in space and that they are also something more: they are known to us also as sights, sounds, etc. No explanation or concise statement of the process of evolution can be satisfactory, or even scientific, which begins by denying the relevance and even the reality of the most important part of our knowledge. If the "first principles" of evolution are to be scientific, they must be inductions drawn from observation and based on some similarity in the phenomena observed, in which case, and in which case alone, they will apply to both classes of phenomena, mental and material. If any "principle" is true of one class alone, it is shown thereby not to be a "first principle": it is not universally applicable.

This raises the question whether there can be any first principles in this sense, whether mind and matter are, to some extent, subject to the same laws; or whether the resemblances which are sometimes drawn are not merely metaphors more or less expanded. Thus we speak of "weighty" objections; but will anyone maintain that ideas are subject to, or exemplify, the law of gravitation? We speak of ideas as "coherent" or "incoherent"; does anyone suppose that they stick together in the same way and from the same causes as material objects cohere?

Mr. Herbert Spencer has written a chapter[21] under the title "Society is an Organism," in which he points out many resemblances between society and an organism. But Mr. Spencer himself "distinctly asserts"[22] that the resemblances imply nothing more than that in both society and organisms there is "a mutual dependence of parts." That is to say, sociology does not herein "exemplify" some of the laws of biology, but sociology and biology both exemplify certain laws which hold good wherever there is a mutual dependence of parts.

Again, Mr. Spencer says[23] that "evolution is definable as a change from an incoherent homogeneity to a coherent heterogeneity, accompanying the dissipation of motion and integration of matter"; and, having shown how and why the homogeneous and the incoherent in the domain of physics tend to become coherent and heterogeneous, he proceeds to show that there is a similar process in the evolution of knowledge, and to say "these mental changes exemplify a law of physical transformations that are wrought by physical forces."[24] Now it doubtless is a fact that with intellectual development there goes a more accurate discrimination of differences at first unnoticed, a readier perception of resemblances at first undetected, a consequent segregation and classification of ideas, and a recognition of heterogeneity where homogeneity was at the first glance supposed to prevail. Doubtless, too, as a result of this process, there is greater coherency in our ideas. But is all this anything more than expanded metaphor? If it is something more, how can these mental changes "exemplify" a law of physics when ideas neither stick physically to each other nor gravitate to one another like the particles of the original, homogeneous, nebular mass? If mental and material phenomena can to some extent obey the same laws, and these laws are scientific inductions, there must be some resemblance between the phenomena.

That resemblance cannot be physical or spatial, because mental phenomena do not occupy space, or possess weight, or exist in three dimensions. As far as one can see, it consists in two points: both classes of phenomena (1) are objects of thought and (2) are displays of force or power. This implies that movements in space are displays of the same force as is manifested in the non-spatial movements of thought. The force which is displayed in consciousness as Will appears in space as motion. Both classes of phenomena, however, are not only displays of force, but also objects of thought. The reality of a phenomenon of either class consists in its being the manifestation of Will to or in consciousness. The reality of the two classes is co-extensive with their similarity, and is the sole foundation for any true inferences or justifiable generalisations about them.

If the law of "the instability of the homogeneous" is a first principle, and is a scientific induction based upon a real similarity between the mental and material phenomena of which it is offered as an explanation, it becomes interesting to inquire how far the similarity extends. In the case of mental evolution the essential feature of the process is that the mind gradually comes to perceive resemblances and to discriminate differences which, though they were present all the time, were not at first appreciable. In other words, the apparently homogeneous was, from the beginning, really heterogeneous. Now this fact, which is true in the sphere of mental evolution, finds its exact parallel in the evolution of the material universe, if the account given above of mechanical compounds and chemical combinations be true. What appears first in the process of evolution, and is exemplified by mechanics, is matter apparently inert. But when the particles of this apparently inert matter enter into chemical combinations with one another they reveal a fresh set of properties, quite different from those exhibited by them previous to their combination; and, when they enter into physiological relations, they display yet further additional properties. This progressive manifestation it is, and not the accompanying "dissipation of motion and integration of matter," which constitutes evolution in the material world, and finds its exact parallel in mental evolution. In both cases we have Will manifested as object of thought; and in both cases we judge most truly of that which is manifested when we judge it by its most complete manifestation. In both cases the apparent homogeneity is not the ultimate fact underlying everything, but is only the first-fruits of that which is yet to come.

FOOTNOTES:

[8] _First Principles_, § 46.

[9] MILL, _Inductive Logic_, bk. iii. ch. xii. p. 549.

[10] _Ibid._

[11] _First Principles_, ch. iii. § 46.

[12] SETH, _Chambers's Encyclopædia_, _s.v._ "Philosophy."

[13] KIRCHOFF, _Vorlesungen über mathematische Physik_, i. p. 1.

[14] MERTZ, _History of European Thought in the Nineteenth Century_, i. pp. 382, 3, note.

[15] LOTZE, _Microcosmus_, E. T., ii. p. 718.

[16] LOTZE, _Microcosmus_, E. T., ii. p. 718.

[17] MILL, _Inductive Logic_, bk. iii. ch. vi.

[18] MILL, _Inductive Logic_, bk. iii. ch. vi.

[19] CLAUDE BERNARD, quoted in _L'Année Sociologique, première année_.

[20] _Principles of Biology_, v. § 30.

[21] _Principles of Sociology_, vol. i. part ii.

[22] _Ibid._, § 260.

[23] _First Principles_, § 127.

[24] _Ibid._, § 153.

VII.

NECESSITY

We have seen that if material things can alone be treated of by science, if things which can be seen and handled are alone amenable to the methods of science, then there can be no science of mind, and no scientific laws to regulate mental phenomena. In the same way, if the field of evolution is completely filled by the redistribution of matter and motion, then there is no room left in the theory of evolution in which to accommodate the history of ideas or of morals, there is no evolution of thought or morality, no continuity between higher and lower in the intellectual development of man and the brute.

We may admit that the methods of mental and moral science, of sociology and political economy, are not identical with those employed by physics or chemistry or astronomy. But we cannot admit that the facts which, if not the proper study of mankind, are at any rate of the greatest interest to man, are not subject to or part of the process of evolution, and cannot be reduced to scientific law and order. The methods of the philosophical sciences may not be the same as those of the exact sciences; but neither are the methods of chemistry those of astronomy--just as the instruments of the astronomer are not those of the chemist. The exactness which is attained by those sciences that can apply the methods of mathematics to their subject-matter cannot be rivalled by philology or psychology. But it is not to all the material sciences that the mathematical methods can be applied: meteorology deals with matter in motion, but not yet with exactitude. The intangible and invisible, but none the less real, facts of our mental and moral experience can be measured to some extent by the statistics and averages and curves employed by the sociologist, the demographer, and political economist: the intensity of a desire may be estimated roughly and relatively by the "effective demand" for its object, the will to live by the number of suicides.

Again, we may admit that the laws of the exact or material sciences do not extend to mental science, without thereby forfeiting the right to subject mental phenomena to scientific investigation and analysis. Chemistry does not cease to be a science because chemical affinity cannot be exhibited as a case of the gravitation formula. Need psychology renounce the claim to be a science because the laws of the association of ideas cannot be deduced, say, from the laws of motion?

Of course, if science has no other object than to describe with mathematical accuracy the exact way in which material things move, if no method is scientific which does not result in such a formula, and if no generalisation, however true, is scientific which does not formulate motion in space, then, indeed, it is unscientific to talk of the evolution of mind and thought, of man and of society.

On the other hand, the movements of material things in space are facts of which we are aware, phenomena of which we are aware through our senses; in a word, they are sense-phenomena. We are aware of them as existing simultaneously and in combination, or as succeeding one upon another; and no truth, even of the most mathematical and exact of the sciences, does, or can do, more than express with mathematical exactness the precise conditions under which these sense-phenomena co-exist or follow one another, or the precise conditions without which such co-existence or sequence cannot take place. A mathematical science dealing with material things states only and always that certain sense-phenomena occur invariably and uniformly under certain conditions. The exact sciences move within the limits of the Uniformity of Nature and the law of Universal Causation; and their subject-matter consists of sense-phenomena, _i.e._ of things which, as known to science, are objects of perception to some mind.

But sense-phenomena are not the only mental phenomena of which we are aware: there are ideas which we do not see or handle, or smell or taste, but of which we are nevertheless distinctly conscious. Thought has its movement, ideas have their co-existence and sequences, the association of ideas has its laws. There is a uniformity of human nature as well as of external nature; there are conditions under which certain actions are always performed, and without which they would never be done. Whether the body of propositions in which these conditions are formulated be accorded or denied the name of science, matters little. But it is difficult to see what are the so great differences between these phenomena and sense-phenomena that make the latter amenable and the former insusceptible to scientific treatment. Is it that ideas are invisible? So is weight, yet the gravitation formula is scientific. Is it that thought is impalpable? So is colour, so is sound--yet there are optics and acoustics.

Be this as it may, what makes things material susceptible to scientific treatment is a quality which is not peculiar to them, but which is shared by them in common with things immaterial: it is that they are objects of which the mind is immediately aware, phenomena present to some consciousness, and that they are phenomena which appear in consciousness as co-existent and successive in certain definite uniform modes which can be detected by thought and formulated in general propositions, or laws.

If the theory of evolution comprehends all things, mind and morals as well as matter and motion; if the law of continuity connects all things together, immaterial as well as material, in a process which moves without break or interruption; it is because all things agree in the fact that they are presented (whether in sense or in idea) to the mind, and because they are presented in the continuity of consciousness.

But the object of the scientific mind is not to observe and record all the phenomena presented to it in the continuity of consciousness. On the contrary, it neglects and rejects many; but always with a purpose, viz. that of ascertaining and describing, as precisely as possible, the conditions under which a given co-existence or sequence occurs (and therefore may be expected to recur) and without which it fails to occur. In other words, science assumes that everything has a cause, and that in accordance with the uniformity of nature what has happened once will happen again in the same circumstances; that a cause will, in the absence of counteracting causes, produce its effect. Without these assumptions science cannot treat of any subject: no department of knowledge can be dealt with scientifically if these assumptions are not admitted with regard to that department. On the other hand, if by the aid of these assumptions we are enabled to reduce any set of phenomena to law and order, our success is of itself sufficient ground for regarding the assumptions as warrantable and justifiable. For science, at any rate, the only question is whether as a matter of fact they do enable us to determine under what conditions given co-existences or sequences will ensue, or what conditions such a co-existence or sequence necessarily implies.

With regard to human activity, mental and physical, it is plain matter of fact that such uniformities of sequence and co-existence not only can be but are demonstrated to prevail; and the extension of the scientific principle of cause and effect to the domain of human will and action is scientifically justified. The comparative sciences which deal with man and his works and words--archæology, anthropology, philology--are perpetually engaged in demonstrating, with fresh proofs every day, the uniformity of human nature: in similar circumstances men have always behaved in similar ways. To satisfy the same needs, they have manufactured similar instruments at similar stages of development: flint arrow-heads from Mexico or Japan resemble those taken from British barrows; the pottery of early Greece is hard to distinguish from that of Peru; the purpose of many stone implements of unknown antiquity has been discovered by a comparison of the use to which similar tools are put by savages still existing. That man's words, as well as his works, exhibit law, order, and uniformity in their growth, as well as in their phonetic decay, is shown by the science of comparative philology. That in the face of the same problems similar analogies have been used to produce similar solutions, is revealed by comparative mythology: the imagination, which might have seemed most free to throw off the trammels of law and of monotonous uniformity, falls in similar circumstances into very similar grooves.

If the will of man is not revealed in the things which he makes, in the words which he speaks, and the thoughts which he thinks, it is difficult to know where to look for its manifestation. If, on the other hand, it is manifested in these ways, then, whether it be free or not, it is clearly uniform in its action; and the extension to it of the law of causation seems fully justified by the results.

The recognition of the universality of the law of causation must not, however, be supposed to carry with it any implication that there are no differences between, say, the organic and inorganic, or that the laws of the one are identical with or deducible from those of the other; the association of ideas may be a scientific and established fact, and yet not obey the same laws as the adhesiveness of material substances. What unites all things into a continuous, coherent, and systematic cosmos, into a scientific whole, is first the fact that, whether phenomena in sense or phenomena in idea, they are all objects of thought; and next the fact that they all exhibit the universality of causation and the uniformity of nature.

Whether this uniformity which binds man and nature into one consistent whole is a uniformity of will or a uniformity of necessity, is quite another question. It is a metaphysical and not a scientific inquiry; and the metaphysical answer, whatever it may be, is one for which science does not and need not pause. So long as nature is granted to be uniform, it matters not to science whether the uniformity is of necessity or is freely willed. In either case the sequences or co-existences described by science will continue, under the circumstances described, to happen as described.

It is, however, commonly assumed that actions which are uniform are, by their very uniformity, proved to be necessitated; and that unless what happens was bound to happen, there can be no uniformity and no science. Hence on the one hand the recognition of the freedom of the will has been denounced as fatal to all scientific conceptions of human nature; while on the other hand the uniformity of human nature and action has been denied as being inconsistent with the freedom of the will. The one side has pointed to one set of facts, which prove irresistibly that men do will the same thing under the same circumstances. The other side has pointed to the equally undeniable fact of our consciousness of freedom.

The essential feature in our consciousness of freedom is our conviction that in the present we can do or abstain from doing a contemplated action, and in the past, though we did the thing, we might have abstained from it or have done something else. Now, whether this possibility that what took place might not have taken place is a real one or only a delusion, matters not to science. If real and true, it is indeed fatal to one particular metaphysical theory, viz. that every event which ever occurred was bound to occur and could not have happened otherwise; but it leaves every truth of science, every one of those concise descriptions of what takes place under given circumstances, absolutely intact. The freedom of the will is anathematised in the name but not in the interests of science.

That becomes clear when we reflect that the laws of science are, and do not pretend to be more than, hypothetical statements. The gravitation formula does not state that bodies do as a matter of fact actually fall at the rate of sixteen feet in the first second, and so on. The statement, if made, would be untrue: a feather floats much more slowly to the ground. Still less does the formula affirm that all bodies move towards each other--and for a very good reason: many bodies are at rest. The formula makes no definite statement as to what actually does occur: it merely states what would or will happen under certain circumstances; and it is doubly or trebly hypothetical. First, it asserts conditionally that if, and only if, bodies are free to move, they will tend to move towards each other at the rate of sixteen feet in the first second, and so on. Next, even if this condition be fulfilled in a particular case, and a given body is free to move, say, towards the earth, the law of gravitation does not assert that the body will absolutely, or unconditionally, or of necessity fall sixteen feet in the first second: it only affirms that the body tends to move at that rate, and the word "tends" conveys in its meaning a second hypothesis. What is meant by saying that a body tends to fall, or tends to move in a straight line, is simply that the body will fall or move in the direction or at the rate mentioned, provided that nothing happens to prevent it. The law of gravitation then, like every other law of science, from the very terms in which it is stated, contains two hypotheses: _if_ bodies are free to move, then they _tend_ to move at a certain rate. Further, like every other law of science, it is based on a third hypothesis, which, as it is assumed by all scientific laws, is not expressly referred to by any. That third hypothesis is that nature is uniform: if a body is free to move it will, in the future as in the past, tend to move at a certain rate, provided that nature is uniform.

Now, throughout all this, it is obvious that science knows nothing about "necessity." Indeed, it is obvious that science, by the trebly hypothetical form of all its laws, has taken particular pains to avoid prejudging the question whether what happens was bound to happen. As we have already said, science takes care to frame its statements in such a way that they are quite independent of metaphysical theory, and will remain as true within their limits if the theory of necessity prove erroneous as they will if it turns out to be correct.

Nor can it be said, thus far, that the laws of science lead us to the theory of necessity as their logical conclusion. It may be true that if I walk over a precipice I shall fall to the bottom, in accordance with the law of gravitation. But it does not logically follow that therefore I must walk over. It may be true that a suspension bridge will fall in the same way, if the supports be removed; but it does not follow that they are therefore bound to give way. It may be true that if nature is uniform certain sequences will happen; but it does not therefore follow that nature must be uniform. In other words, the theory of necessity, if true, cannot be based on science, but must rely on some metaphysical considerations. Science does not undertake to prove even that nature is uniform, much less that it is uniform of necessity. The opposite theory, that the uniformity of nature or of human nature is due to the action of a will freely manifesting itself as uniform, may be considered superfluous from the scientific point of view. But the theory of necessity from the same point of view is equally superfluous. As long as events do happen uniformly, science has all she wants--whether their uniformity is of will or of necessity is for her quite a superfluous question. And if science were all that man wanted, these rival metaphysical theories would be of no interest to him either. But the persistency of the attempt to extract some support for the metaphysical theory of necessity out of the facts of science shows that men of science, being men, must have their metaphysics.

Are there, then, other facts of science, or assumptions essential to science, which require the metaphysical theory of necessity as their presupposition or entail it as their natural consequence? Probably the reply will be that there is one such principle: that of the Universality of the Law of Causation. The assumption that everything _must_ have a cause may be on the part of science a pure assumption, and one which, like the Uniformity of Nature, cannot be proved by science; but it does, it may be said, assume the existence of a necessity in things.