Outlines of psychology online

the Amphioxus, has only a spinal cord, no brain ; and in the
lower classes of vertebrates the brain is developed in a much lower
degree than the spinal cord.

The more the cerebrum preponderates over the other brain-
organs, the more highly do we find the conscious life developed.
The higher centres occupy far more room in the brain of man
than in that of animals, the immediate centres for sensation and
muscular movement having apparently the ascendency in the
latter. The greater or smaller wealth of convolutions in the brain
is also proved to stand in connection with the higher or lower stages
of development of conscious life. The brain of the more intelligent
species of dog has more convolutions than that of the less in-
telligent species ; man is in this respect far in advance of apes,
which in other respects come so close to him in structure ; the
cerebral hemispheres of distinguished men are very large, and rich
in convolutions.

With this agrees the constitution of the brain in the foetus and the
new-born infant. In the earlier states of the foetus the cerebrum,
in man as in all vertebrates, lies in front of the other portions of

1 Die Pathologit und Therapie der psychischen Krankhtitrn, 2nd ed.. p. j6.

2 Exner, Phj siolcsU der Grossliimrinde {B.trm3inn'i llandbuch, ii., 2) p. ij;.



54 OUTLINES OF rSVCTTOLOOY [ii

the brain without covering them. In the course of development it
covers (in man and to some extent in apes) first the pons Varolii
and ultimately the cerebellum. The cerebrum of new-born
children — both in structure and in power of functioning — is little
developed, while the subordinate brain-apparatus is ready for
immediate use.

Finally, it is proved by experiments that sensations arise only if
excitations are conveyed from the surface of the organism to the
brain, and that voluntary movement is possible only if the motor-
centres in the brain are uninjured. By removal of the cerebrum
the conscious life of animals which can survive the operation is
weakened, deliberation and initiative are lost. Conversely, a dull
and undeveloped conscious life (as in idiots) is connected with a
defective nourishment and defective development of the brain ; and
the advancing dissolution of conscious life in mental disease is
accompanied by gradual dissolution of the brain, especially in the
cerebrum. If the veins which supply arterial blood to the brain
are tied up, there ensues an unconscious state, which leads to
death.i

8. Now, whither are we led by this formal agreement and this
actual connection between conscious life and the life of the
brain ?

No hypothesis can be admitted which does not allow due weight
to all the facts we have brought forward. In the nature of the
case only four possibilities can be conceived ; (n) either con-
sciousness and brain, mind and body, act one upon the other as
two distinct beings or substances ; {/)) or the mind is only a form
'or a product of the body ; (c) or the body is only a form or a
product of one or several mental beings ; {d) or finally, mind
and body, consciousness and brain, are evolved as different
forms of expression of one and the same being. These several
possibilities we now proceed to examine, relying on the results
set forth in the preceding sections. Whichever we may prefer,
it is clear that we can adopt it only as a provisional hypothesis.
At the same time it must be carefully borne in mind, in
the following examination of the different hypotheses, that,
as already noted (II., I.), we are here concerned with the
relation between mind and body only from the point of view of
experiential psychology, and are not in search of a final philo-

1 Exner, pp. 193-206 ;• Griesinger, pp, *i3-4+4 ; Twdjsu, Etude midicoUsale sur la.
Foiit. znd ed., pp. 85-89, J19.



n1 MIND AND liODY 55

sophical or metaphysical theory. Possibly the result arrived at
must be reconsidered before it can take its place in a philosophical
theory : but our present task is not the establishment of such a
theory. The hypotheses now to be examined lie on the borders
between experiential science and metaphysics ; but we are con-
cerned with them only from the point of view of the former.

(a) The ordinary notion is that the mind acts upon the body
and the body upon the mind. It is perhaps thought that we feel
this immediately, although this seems to be at once contradicted
Iw the want of agreement as to the existence of a mind, independent,
and distinct from tlic body, and by the fact that in any case it is
only indirectly that we have come to know with which part of the
body the mind is more particularly connected. " But are there
not unquestionable facts which prove the truth of this view? An
excitation of a sense-organ is transmitted to the brain, and there
passes into sensation, while conversely, our will is able to set
the body in motion ! " But it is just the relation between what
passes in the brain and states of consciousness that is the question,
and if the facts were as stated, we should have no reason for
asking it ; we should already know the answer. If the state of
the brain, with which the sensation or the decision is connected,
does not itself become an object of consciousness, it is impossible
to discover whether tnere really is a causal relation, or a
relation of interaction, between the brain and consciousness or
not. There is no justification, therefore, for maintaining, as
a fact, that a bodily process causes a mental process, or the
reverse. And it will be admitted, on further reflection, that, even
if physiology could give a scientific explanation of the condition
of the brain which ensues when I am struck by a stone, the
feeling of pain aroused in me would not be included in the
physiological explanation. Physiology, like every natural science,
explains a material process by means of other material processes.
Its assumptions are not framed to include a case in which one
member of the causal relation shall be spatial, the other non-
spatial.

The supposition that a causal relation may exist between the
mental and the material is contrary to the doctrine of the
" conservation of energy." For at the point where the material nerve-
process should be converted into mental activity, a sum of physical
energy would disappear without the loss being made good by a
corresponding sum of physical energy. To this it has been



56 OUTLINES OF PSYCHOLOGY [ii

answered that it is, indeed, inconceivable how material activity
can pass into mental activity, but that, taken strictly, every
transition, every conversion of force, is inconceivable to us ;
and, moreover, that the doctrine of the conservation of energy
requires only that a certain corresponding sum of energy shall
come into action instead of that which has disappeared, it being
all one whether this equivalent be of a physical or a psychical
nature. But this would be a bold and unwarranted extension of
the doctrine of the conservation of energy, which, in the form in
which it lies before us, is a purely physical doctrine. Such an
extension would imply the possibility of finding a common measure
for the mental and the material. Now what denominator is
common to a thought and a material movement, or what common
form serves for both? Until such a common form can be
pointed out, all talk about an interaction between the mental and
the material is, from a scientific point of view, unjustified. So
long as we confine ourselves to the material we are on safe
ground, and so long as we confine ourselves to the mental we
are on safe ground ; but any attempt to represent a transition from
physical to psychological laws, or conversely, brings us face to
face with the inconceivable. In the causal concept, as in all
concepts which condition our apprehension of reality, there is
contained an epistemological problem. As at all points where we
approach the boundary lines of our knowledge, difficulties arise,
but a difficulty multiplies itself when the causal concept is
employed to connect two factors which have no common measure.

The ordinary notion, indeed, leads involuntarily to a doctrine
of homogeneity, since mind is apprehended as material w^hen
it is thought of as affected by material movements, and the
material is turned into something mental when regarded as open
to mental influence (as Plato makes reason " persuade " matter).

It will easily be seen that it avails nothing to say that the mind
may not indeed be able to increase the sum of physical energy
in the world, but that it can alter the direction of the applied
energy. A physical movement does not change its direction
except under the influence of a physical force of a certain strength.
So that this subterfuge also of necessity makes the energy of
consciousness a physical energy.

The application of the causal conception presupposes not only
a common measure, but also a, difference in time. The question
which has been raised, as to whether cause and effect are



iij MIND AND BODY 57

simultaneous or not, rests partly on a misunderstanding, and in
any case does not concern us here. On the other hand, it cannot
be denied that the conception of causality would never have been
formed had not phenomena been subject to change. If everything
were uniform and unchangeable, we should have nothing about
whose cause we could inquire. The relation of causality pie-
supposes the occurrence of an event. If the relation between mind
and body, or consciousness and brain, is a causal relation, there
must be a difference of time between the process in the
brain and the act of consciousness. This, however, is contrary
to the view suggested by physiology. As we have seen, the aim
of modern physiology is to conceive all organic processes as
physical or chemical. It does not boast that it has explained the
origin of organic life ; it maintains only that where it has attained
to a comprehension of anything in the region of organic life, this
has in every case been by the tracing back of organic phenomena
to physical and chemical laws. If, then, there is a transition from
physiological function to psychological activity, from body to mind,
physiology at any rate, working with its present method, cannot
discover it.

To admit such a transition implies that the physiological pro-
cess is interrupted at certain points, namely when the stimulus
becomes a sensation, to be resumed by a psychological process,
under changed conditions, when the mind has recovered from
the material stimulation and responds to it with an act of
will. The idea of a causal relation between mental and material
forces upon physiology an interruption of this kind. But physio-
logy will hardly be induced ever to admit such interruption. Apart
from the physical, which is also a physiological, difficulty
involved in the breach of the doctrine of the conservation of
energy, the nerve-process must from the physiological stand-
point be conceived as a connected course. In this depart-
ment very much is still unexplained.' The relation between
nerve fibres and nerve-cells is very obscure ; the physical pro-
perties of the ganglion-cells, and consequently the physical origin
of the simplest reflex movement, are not yet understood ; it is
not even quite certain that the ganglion-cells form the connecting

' Cf. Ditlefsen, Menneskets Histoiog^ie ("Histology of M.in") (Copenhasen, 1879),
p. 582. " The new discoveries as to the structure of the iierve-tibres have not advanced
our knowledge of the relation between them .ind the cells ; for the time being we must
tentatively hold that the nerve-cells are centres of the nerve-fibres, and address our
histological investigations to the task of producing a satisfactory morphological under-
standing uf this physiological fucL"



58 OUTLINES OF PSYCHOLOGY [ii

link bet'.vcen the afferent and efferent nerve-fibres. Nor has it
been possible to point out the anatomical connection between the
centres of the centripetal and those of the centrifugal nerves in the
spinal cord.^ But in spite of all this, physiology cannot permit its
boundaries to be invaded from without. Its fundamental thought
is the universal coherence of organic life ; it tries to explain the
more complicated processes by reducing them to the simpler ; it
learns from the lower phenomena how the higher are to be under-
stood, for it takes the principles of structure and of activity to be
the same throughout. Thus e.g. the doctrine of reflex move-
ments throws a light on the way in which the highest cerebral
functions are to be explained,^ though we are not thereby justified
in concluding straight away that all cerebral activity is reflex
activity. So far as we can speak of final results in the physiology of
the brain, this represents the brain as a republic of nerve-centres,
each with its function, and all in interaction ; but there is nothing
to indicate the possibility of the physiological process breaking off
at any point to pass into a process of a wholly different kind.

Of course there is always one way of escape ; to deny the
universal validity of the doctrine of energy. This doctrine is not
experimentally proved, and as we have seen, cannot, strictly speak-
ing, ever be so proved. But according to the general rules of
methodology, we may not, in framing our hypotheses and in judg-
ing of them when framed, enter into conflict with leading scientific
principles. And in modern natural science, the doctrine of energy
is such a leading principle. If, therefore, an hypothesis is in
conflict with this doctrine, the fact tells at once decidedly
against it.

The ordinary doctrine of interaction (the doctrine of the injluxus
physicus, as it was called in earlier times) is presented in a stricter,
more metaphysical, and in a vaguer, more indefinite, form. In
its metaphysical form it appeared in the writings of Descartes,
who conceived of mind and body as two substances, absolutely
distinct in kind, but nevertheless acting on one another. Here
was made the hasty attempt, already mentioned, to prove the soul

1 C. Lange Rygmarvens Patologi ("Pathology of the Spine"), p. 24; Eckhard,
Physiologic des Rilckenmarks unddesGehirns{\\v.xm.3.mi, ii., 2), pp. 7-19, 61 seq. [Ferrier,
p. 60 seq. (l'r.)l

2 After Marshall Hall (1833) had laid down the theory of reflex-movement, Lay-
cock (1840) pointed out that its principle must be applied to the physiology of the brain
also. ("On the Reflex Action of the Brain. The British and Foreign Medical Revifw,
1845). Independently, as it seems, ofLaycock, Griesinger expressed the same thought in his
treatise " Ucber psychische Reflcxaktionen " (Archiv fiir physiologische Hcilkunde,
1843-)



ii] MINI) AM) lUJDV 59

to be an independent substance, a view which exchanged the
standpoint of experiential psychology for that of metaphysics.
But it was precisely the distinct and clear form which Descartes
gave to the current doctrine that to an extraordinary extent
contributed to lay bare its weak points. It was abandoned, as the
history of philosophy shows, as soon as it was set forth with all its
consequences. To Descartes, therefore, belongs the credit of
having set the problem of the relation between mind and body.
For to the current notion in its vaguer form there is no difficulty in
this relation. With legitimate heedlessness, the practical usage of
speech ignores theoretical difficulties. Ordinary language no more
regards the fact that physiology and psychology are opposed to the
notion of brain and consciousness acting on one another, than it re-
spects the doubt of Copernicus as to the sun really moving round
the earth. Moreover, the practical usage of speech has been
formed under the influence of a partly spiritualistic, partly
materialistic, metaphysics.

(l>) An end is put to this inconsequence and vagueness, when one
of the two factors, whose connection is the point in question, is
without more ado struck out. And since the perception of the
external, material -world takes the leading part in our ordinary,
every-day ideas, while our inner self-consciousness is with diffi-
culty educated to a like clearness and distinctness, it is perhaps
the most natural thing to identify materiality with reality, and
to conceive of the mental as a form or effect of the same.
Certainly materinlis>n is historically older than the current doc-
trine of an interaction. Homer and the earliest Greek philo-
sophers (before Socrates and Plato) are materialists ; even in the
teaching of the Christian Fathers before Augustine materialistic
notions predominated. The older forms of materialism did, how-
ever, draw a distinction between mind and body, though regarding
both as material substances [cf. 15). Modern materialism does
away with this duality, usually treating the mental as a function or
a side of the material. In modern times materialism has found a
solid basis in the doctrine of the conservation of matter and energy
and in that of physiological continuity. It has full justification as
against every spiritualistic line of thought which leads to the setting
of external limits to the series of physical and physiological causes.
As a method of natural science, materialism is unanswerable. But
it is another affair when the method is converted without more ado
into a system. It has a perfect right to treat all changes and



6o OUTLINES OF PSYCHOLOGY [n

functions of the organism, in particular of the brain, as material ;
but as a system it goes farther, and maintains that the phenomena
of consciousness are only changes or functions of the brain, and in
this consists its encroachment.

Karl \'ogt gave in his time great offence by declaring (in his
Physiological Lfiicrs) that " as contraction is the function of the
muscles and as the kidneys secrete urine, so, and in the same way,
does the brain generate thoughts, movements and feelings." It might
appear as though he had here left a choice between two ideas : to
conceive of thoughts either as matter or as moveinent. The first
mode of conception, though it comes closest to direct apprehension,
and was on this account chiefly adopted in the ancient materialism,
has on closer consideration something so quaint about it, that it
needs no further discussion. And in Vogt's comparison of the origin
of thought and the origin of secreted matter doubtless the chief
emphasis is to be laid on the secreting activity, not on the product.
The principle, however, remains the same. Even among cautious
physiologists with some philosophical training, the doctrine that
conscious activity is a function of the brain may be sometimes met
with. And yet it would seem as though just the strict physiolpgical
use of the term function must contradict such a doctrine. To
say, e.g., that contraction is the function of the muscle only means
that it is a certain form and a certain condition of the muscle in
movement. As Goethe has put it, " Function ist Dasein in
Thatigkeit gedacht." The muscle when functioning is just as
material as the muscle when at rest, and that which has not the pro-
perties of the material cannot be the form of activity of something
which is material. The conception function (in the physiological
sense) ' implies, just as much as the conception matter or product,
something presented as an object of intuition in the form of space.
But thought and feeling cannot be pictured as objects in space or
as movements. We get to know them, not by external intuition,
but by self-perception and self-consciousness, — a source from which
the physiologist also draws, without being always clearly conscious
of the fact, when he incjuires into the relation of conscious to
organic life. By many round-about ways it has been at last dis-
covered that certain definite phenomena of consciousness are con-
nected with the function of certain definite parts of the brain. It is

1 In the mathematical sense, however, we have a perfect right to say that consciousness
is a function of the brain, since experience shows a certain proportionality between the
degrees of development of consciousness and of the brain. Conscious activity would then,
to spealc precisely, be a mathematical function of the physiological function of ihc brain.



ii] MIND AND BODY 6i

not even doubted that the highest of all the activities of conscious-
ness have their corresponding cerebral functions,— as the most
beautiful melodies are not too sublime to be expressed by notes.
But activity of consciousness and cerebral function always come to
be known through different sources of experience. The encroach-
ment of materialism consists in the fact that it effaces this essential
distinction witliout more ado. In quietly attributing to the brain
the power of being conscious, or in even perhaps making the brain
the subject of the manifestations of consciousness,' materialism is
really returning to a fanciful mythological standpoint.

We are attending here principally to empirical or phenomena-
logical materialism, that is to say, to the view which holds as the
direct result of experiential science, that the phenomena of con-
sciousness are forms or effects of material phenomena, so that all
reality may be traced back to movements in space. Here we
move in the region not only which we ourselves prefer, but in
which materialism has always believed itself to move. I^Iaterialism
has never observed that, even if all its assertions are admitted to
be just, it yet always overlooks something which gives rise to
a new, and for it a terrible problem ; namely the circumstance,
that movement in space is known to us only as an object of
our consciousness. For the theory of knowledge, such notions
as consciousness, idea, and intuition lie deeper than such notions
as matter and movement. For this reason an absolute and de-
cided materialism was possible only in ancient times, before the
awakening of more deeply penetrating philosophical reflection.
Democritus is the only consistent materialist. None of the modern
materialistic writers can speak with the calm and the certainty with
which Lucretius in his majestic verses sets forth the doctrine of
Democritus. Modern materialists for the most part confess that,
even if we can reduce everything to matter, yet we cannot know
what matter is in itself. Thus La Mettrie, Holbach, Cabanis,
not to speak of the wild, rambling inconsistencies of the most
recent writers (Biichner, Aloleschott).

But what wc have here urged against materialism, is not the
epistemological inconsistency exhibited in its desire that conscious
life shall recognize, as the absolutely original and only reality,

1 Ch. Robin, ^..e. defines "sensibiliti^" as follows {Anat. ft Physiol. Cilliilaire), p.
540, " Ce mode de l.i novrilite est ch.iractijrise' par ce fait, que les c'le'ments nerveux qui
eii jouissent, apres avoir recu une impression du dehors, la transmettent de ce point a un
autre oil (Is (sU) la perijoive'nt." A similar mode of expression is employed by Broussais.
But what idea is really conveyed by nervous elements perceiving and apprehending



62 OUTLINES OF PSYCHOLOGY [il

something which is given only as an object of consciousness, and
which can be represented and recognized only through the activity
proper to consciousness. Our task is only to find out to what
view the given facts impel us ; and the result of our criticism of
materialism is that it offends against the conceptions derived from
experience itself.

{c) In treating of moiisiic spiritualism, as the third possible
hvpothesis, we must always hold fast the distinction between a pheno-
menological and a metaphysical way of looking at things. Very many
confusions relative to the problem before us are the result of over-
looking this distinction. Spiritualism, like materialism, has almost
always confounded metaphysical and empirical results. Monistic
spiritualism is the view according to which the mind is a mental
(geistige) substance, and the mental is the only reality ; everything
material, all movement in space, is but an outer form of a mental
life. Through this last view monistic spiritualism is distinguished
from the dualistic spiritualism introduced by Descartes. It is
based on the impossibility of explaining the mental by the
material, and on the fact partly overlooked, partly undervalued, by
materialism, that our conception of matter is a mental product,
and that, apart from our conception of it, we do not know what
matter is. Thus the spiritual or mental is -xpriiis, a pre-supposition,
on which all thought rests ; and a reasonable hypothesis is formed
only by the reduction of the less known to the better known. The