The place that will be held by James Clerk Maxwell in the history of
physics is not easy to determine. That it will be a very high place is
obvious, that he will emerge as the greatest of the physicists of the
nineteenth century is probable, but the student of Maxwell must feel
that this kind of ranking is somehow irrelevant, or likely to become
irrelevant, to his peculiar effect. The unique impression produced by
Maxwell’s achievement is not adequately described by being referred to
his “originality.” There are different ways of being original; it is
not a sufficiently penetrating term. A number of Maxwell’s scientific
contemporaries were original men, but one is conscious that they
had more in common with one another than Maxwell had with them. An
exception from this statement is found in W. K. Clifford, who, as has
often been remarked, had a genius curiously akin to Maxwell’s. Both men
were exceptionally _independent_ thinkers, both men resisted the
attraction of the high road; both men, if the term may be permitted,
had a personal and unique angle of approach to the problems of their
time. But this, though true, is not a sufficient description. It is
important that in neither case do we feel their individual quality
to be an eccentricity; their work has a power, and, still more, a
comprehensive serenity, which is never the product of mere oddity--the
oddity, for instance, of a Samuel Butler. If we try to get closer to
this elusive and important characteristic we do not meet with much
success; but we may suggest that the ideas of these men have the
effect of springing from an unusually rich, subtle and comprehensive
_context_. The fundamental ideas of the science of their time were
subtly modified by reception into these minds; they were connected in a
personal and unusual web of implications.
It is doubtless worth noting in this connection that Maxwell, unlike
most of the scientific men of his time, was genuinely interested in
metaphysical speculation. This was not merely another interest of
his; it was, at most, another field of attention; he brought the same
attitude of mind to all the objects with which he was concerned. We
cannot make an exception even in the case of his religious views; to
this man the problems of metaphysics, of physics, of morality, are
almost arbitrary divisions of the one object of his thought. He was
expressing a real difference from himself when he said that some men
seem to have water-tight compartments in their minds. When we study the
kind of homogeneity characteristic of Maxwell’s mental life it is easy
to understand those who call him a mystic. Even as a purely scientific
man, his rational faculty, as evidenced by his mathematical reasoning,
was a distinctly more fallible thing than his intuition. This is not to
say that he was not a fine mathematician, but it is his intuitive grasp
of a physical problem which gives him his high position, and not his
purely mathematical verifications. His mathematics, in fact, was not
always impeccable, as Sir Joseph Larmor points out in the new edition
of _Matter and Motion_. But it is characteristic of Maxwell, that,
even when his proofs were faulty, his results were usually sound. His
own way of confirming a difficult intuition was not to provide a formal
mathematical verification, but to make appeal to easier intuitions--in
fact, to construct mechanical models. He always liked to _see_ the
way things worked. It is important to remember that this desire for a
particular kind of verification was not due to any lack of power to
form abstractions; it was due to something quite different, to a lack
of ease when faced by a purely logical chain of deduction. On Maxwell’s
famous _Treatise on Electricity and Magnetism_, Poincaré comments
that its difficulty resides precisely in its great abstraction. It is
this presentation of his theory to which one has to turn; nevertheless
Maxwell, as if for his private satisfaction, developed some extremely
complicated models which seemed to him to make his theory clearer. It
was doubtless this combination, a great power of abstraction on the one
hand, and a desire for very definite, even unnecessarily definite,
confirmation on the other, which enabled him to be at once extremely
original and remarkably sound.
In his boyhood he was constantly making all kinds of experiments with
common substances, drawing complicated diagrams, constructing solid
geometrical figures, even knitting elaborate pieces of wool-work;
practically all these pursuits were dictated by the same desire, the
desire to see an abstract principle embodied in a concrete instance.
No man was less at the mercy of words. But it was, nevertheless,
the abstract principle with which Maxwell was concerned; he merely
wished to be quite sure that he understood it. His occasional trick of
supplying an unexpectedly simple proof of a difficult theorem is due to
this habit of realisation. Platitudes acquired a wealth of implication
in Maxwell’s hands. During his student life at Cambridge, when he seems
to have been chiefly occupied in making a survey of things in general,
we find the same desire to reduce everything to a few principles; but
the principles must first stand a rigorous examination. Merely vague
unifications provoked his irony, and where no principle could be made
to work, then, in spite of his love for coherent and inclusive systems,
he would admit ignorance. And, in spite of his need for principles,
and the tenacity with which he clung to those that met his need, he
claimed no “absolute” quality for his beliefs. In his own words,
“Nothing is to be _holy ground_ consecrated to Stationary Faith,
whether positive or negative.” And, later, “Again, I assert the Right
of Trespass on any plot of Holy Ground which any man has set apart....”
Such questioning as Maxwell applied to himself was to be applied to
all other men. He was conservative, but not on exterior authority. His
scepticism was, in truth, very profound, and it was always present.
It informs his criticism, which is often extremely penetrating. The
letters he wrote on the death of his friend Pomeroy, shortly after
Maxwell had become a Fellow of Trinity, are very instructive from this
point of view. His distrust of the “rationalisations” that men give of
their beliefs extends to the beliefs themselves. As he says, men “are
ignorant even of their own true faith till something brings it into
action.” This was a deep-rooted conviction with him, and is responsible
for the flavour of irony which is never long absent from his comments
on philosophic matters, indefatigable student as he was. He can direct
this scepticism against himself, as in the entry in his programme of
future study: “4. Metaphysics--Kant’s _Kritik of Pure Reason_
in German, read with a determination to make it agree with Sir W.
Hamilton.” On another occasion he writes to a friend pointing out that,
in reading an author, he had to find out first of all, not what the
author meant, but that it was not what he was convinced must be meant.
A little experience of criticism persuades us that this is, indeed, a
very necessary procedure.
This aspect of Maxwell, as a critic at large, as it were, would
well repay study, and it is unfortunate that our material for it is
contained in a scarcely ideal biography. He differed from the run of
scientific men, whose absorption in one pursuit makes their mental life
unrepresentative; his chief problems are not found in his scientific
writings, and they are the problems of us all. There was nothing
superficial in Maxwell, and he had no easily won conclusions. It is
the path he followed that gives interest to his goal. We should like
to know, for instance, what experiences, what reflections, enabled him
to write: “Long ago I felt like a peasant in a country overrun with
soldiers, and saw nothing but carnage and danger. Since then I have
learned at least that some soldiers in the field die nobly, and that
all are summoned there for a cause.” That Maxwell, either suddenly
or gradually, developed a mystic consciousness of life, is borne
out by many passages of his correspondence. We can attach no other
significance to his description of his “nostrum”: “an abandonment of
wilfulness without extinction of will, but rather by means of a great
development of will, whereby, instead of being consciously free and
really in subjection to unknown laws, it becomes consciously acting by
law, and really free from the interference of unrecognised laws”; and
his letters to his wife, dealing with passages from the Bible, abound
in interpretations which are indubitably mystical. Yet we have no
evidence that he was acquainted with the literature and terminology
of mysticism; he is speaking of personal experiences, not of acquired
doctrines.
The maintenance of a mystical outlook on life, together with a
perfect realisation of the implications of physical science, was
accomplished, in Maxwell’s case, by denying the ordinary conception of
the _direction_ of scientific progress. It is the idea which would
inevitably occur to him, for it is the peculiar merit of his own work
that it was not the result of straightforward progress. He made a new
way of thinking necessary just as, in our own time, Quantum Theory and
Relativity Theory have fundamentally disturbed our most unquestionable
assumptions. The way Maxwell actually approached the problem we have
mentioned was by insisting on what he called, by a mathematical
analogy, the “singular points” of existences, that is, the points where
the equations break down, and he postulated that the more there were
of these singular points the higher the rank of the existence. At a
“singular point” influences which are usually negligible may assume a
dominating importance, and Maxwell saw the science of the future as
being largely concerned with these lapses in continuity--as, in fact,
science since his time has been. In this way he escaped determinism. In
his own words:
If, therefore, those cultivators of physical science from whom the
intelligent public deduce their conception of the physicist, and
whose style is recognized as marking with a scientific stamp the
doctrines they promulgate, are led in the pursuit of the arcana of
science to the study of the singularities and instabilities, rather
than the continuities and stabilities of things, the promotion of
natural knowledge may tend to remove that prejudice in favour of
determinism which seems to arise from assuming that the physical
science of the future is a mere magnified image of that of the past.
This speculation, the problem of evil, and in what sense the individual
may be said to persist in Time, are the kind of questions which
concerned him during the last years of his life. It would be merely
fanciful to mention these things as evidence of that “context” of which
we spoke, but we think it is possible to understand more intimately the
origin of the Electromagnetic Theory of Light if we remember that it
originated in a mind which also constantly entertained these other, and
apparently disconnected, speculations.