LECTURES
ON
THE PHILOSOPHY
OF
THE HUMAN MIND.
BY THE LATE
THOMAS BROWN, M. D.
PROFESSOR OF MORAL PHILOSOPHY IN THE UNIVERSITY OF
EDINBURGH.
IN THREE VOLUMES.
VOL. I.
ANDOVER:
PUBLISHED BY MARK NEWMAN.
FLAGG AND GOULD, PRINTERS.
1822.
CONTENTS.
LECTURE I.
PAGE.
Introduction, 9
LECTURE II.
Relation of the Philosophy of Mind to the Sciences in general, 20
LECTURE III.
Relation of the Philosophy of Mind to the Intellectual Sciences
and Arts, 35
LECTURE IV.
Relation of the Philosophy of Mind to the Cultivation of
Moral Feeling, 50
LECTURE V.
On the Nature of Physical Inquiry in general, 64
LECTURE VI.
On the Nature of Physical Inquiry in general, 80
LECTURE VII.
On Power, Cause, and Effect, 98
LECTURE VIII.
On Hypothesis and Theory, 113
LECTURE IX.
Recapitulation of the Four preceding Lectures, 129
Application of the Laws of Physical Inquiry to the Study of
Mind, 135
LECTURE X.
Continuation of the same Subject, 144
LECTURE XI.
Continuation of the same Subject, 162
On the Phenomena of Mind in General, 167
On Consciousness, 169
LECTURE XII.
On Consciousness, 178
On Mental Identity, 180
Identity irreconcilable with the Doctrine of Materialism, 180
Distinction between Personal and Mental Identity, 182
Shaftesbury's Opinion of Identity, 184
Objections to the Doctrine of Mental Identity, 185
LECTURE XIII.
On the Direct Evidence of Mental Identity, 192
Objections answered, 204
LECTURE XIV.
Continuation of the same Subject, 207
LECTURE XV.
Continuation of the same Subject, 224
Opinion of Mr Locke respecting Identity, 230
Source of his Paradox respecting it, 234
Reflections suggested by his Paradox, 235
LECTURE XVI.
On the Classification of the Phenomena of Mind, 239
LECTURE XVII.
Continuation of the same Subject, 254
On the External Affections of Mind, in general, 262
On the less Definite External Affections, 264
LECTURE XVIII.
On the more Definite External Affections, 269
LECTURE XIX.
On the Corporeal Part of the Process, in Sensation, 283
LECTURE XX.
Particular Consideration of our Sensations, 298
On Smell, 300
On Taste, 301
On Hearing, 305
LECTURE XXI.
Continuation of the same Subject, 312
On Touch, 326
LECTURE XXII.
On the Feelings ascribed to the Sense of Touch, 328
Analysis of these Feelings, 330
LECTURE XXIII.
Continuation of the same Subject, 345
LECTURE XXIV.
Continuation of the same Subject, 358
LECTURE XXV.
On the Distinction between Sensation and Perception, 379
On the Primary and Secondary Qualities of Matter, 384
LECTURE XXVI.
On Dr. Reid's supposed Confutation of the Ideal System, 395
Hypothesis of the Peripatetics regarding Perception, 396
Opinion of Locke--Hobbes--Des Cartes--Arnauld--Le Clerc
De Crousaz, regarding Perception, 399
LECTURE XXVII.
Examination of Dr Reid's supposed Confutation of Idealism 411
LECTURE XXVIII.
Conclusion of the Subject, 427
On Vision,--Analysis of the Feelings ascribed to it, 431
LECTURE XXIX.
Continuation of the same Subject, 442
LECTURE XXX.
History of Opinions regarding Perception, 459
Opinion of the Peripatetics, 462
---- of Des Cartes, 464
---- of Malebranche, 469
---- of St Austin, 472
LECTURE XXXI.
---- of Leibnitz, 474
On the External Affections combined with Desire, 479
Attention, 482
LECTURE XXXII.
Continuation of the Same Subject, 490
On the Internal Affections of Mind, 497
On the Classification of these Affections, 500
LECTURE XXXIII.
On Locke, Condillac, and Reid's Classification of the Mental
Phenomena, 505
New Classification of the Internal Affections, 518
LECTURE XXXIV.
On Simple Suggestion, 523
Advantages resulting from the Principle of Suggestion, 526
On Mr Hume's Classification of the Associating or Suggesting
Principles, 532
LECTURES ON THE PHILOSOPHY OF THE HUMAN MIND.
LECTURE I.--(INTRODUCTION.)
GENTLEMEN,
The subject on which we are about to enter, and which is to engage,
I trust, a considerable portion of your attention for many months,
is _the Philosophy of the Human Mind_,--not that _speculative_ and
_passive_ philosophy only, which inquires into the nature of our
intellectual part, and the mysterious connexion of this with the body
which it animates, but that _practical_ science, which relates to the
duties, and the hopes, and the great destiny of man, and which, even in
analyzing the powers of his understanding, and tracing all the various
modifications of which it is individually susceptible, views it chiefly
as a general instrument of good--an instrument by which he may have the
dignity of co-operating with his beneficent Creator, by spreading to
others the knowledge, and virtue, and happiness, which he is qualified
at once to enjoy, and to diffuse.
“Philosophy,” says Seneca, “is not formed for artificial show or
delight. It has a higher office than to free idleness of its languor,
and wear away and amuse the long hours of a day. It is that which forms
and fashions the soul, which gives to life its disposition and order,
which points out what it is our duty to do, what it is our duty to
omit. It sits at the helm, and in a sea of peril, directs the course
of those who are wandering through the waves.” “Non est philosophia
populare artificium, nec ostentationi paratum; non in verbis sed in
rebus est. Nec in hoc adhibetur ut aliqua oblectatione consumatur dies,
ut dematur otio nausea. Animum format et fabricat, vitam disponit,
actiones regit, agenda et omittenda demonstrat, sedit ad gubernaculum,
et per ancipitia fluctuantium dirigit cursum.” Ep. 16.
Such, unquestionably, is the great practical object of all philosophy.
If it increase the happiness and virtue of human kind, it must be
allowed to have fulfilled, to human beings, the noblest of earthly
ends. The greatness of this primary object, however, perhaps fixed too
exclusively the attention of the moral inquirers of antiquity, who, in
considering man as capable of virtue and happiness, and in forming nice
and subtle distinctions as to his supreme good, and the means by which
he might attain it, seem almost to have neglected the consideration of
his intellectual nature, as an object of mere physical science. Hence
it happens, that, while the systems of ancient philosophy exhibit,
in many instances, a dignity of moral sentiment as high, or almost
as high, as the unassisted reason of man could be supposed to reach,
and the defects of which we perhaps discover only by the aid of that
purer light, which was not indulged to them, they can scarcely be said
to have left us a single analysis of complex phenomena of thought
and feeling. By some of them, indeed, especially by the Peripatetics
and Stoics, much dialectic subtilty was employed in distinctions,
that may seem at first to involve such an analysis; but even these
distinctions were verbal, or little more than verbal. The _analytical
investigation_ of the mind, in all its complexity of perceptions, and
thoughts, and emotions, was reserved to form almost a new science in
the comprehensive philosophy of far later years.
If, however, during the flourishing periods of Greek and Roman letters,
this intellectual analysis was little cultivated, the department of
the philosophy of the mind, which relates to practical ethics, was
enriched, as I have said, by moral speculations the most splendid and
sublime. In those ages, indeed, and in countries in which no revealed
will of heaven had pointed out and sanctioned one unerring rule of
right, it is not to be wondered at, that, to those who were occupied
in endeavouring to trace and ascertain such a rule in the moral nature
of man, all other mental inquiries should have seemed comparatively
insignificant. It is even pleasing thus to find the most important of
all inquiries regarded as truly the most important, and minds of the
highest genius, in reflecting on their own constitution, so richly
diversified and adorned with an almost infinite variety of forms of
thought, discovering nothing, in all this splendid variety, so worthy
of investigation, as the conduct which it is fitting for man to pursue.
But another period was soon to follow, a period in which ages of long
and dreary ignorance were to be followed by ages of futile labour,
as long and dreary. No beautiful moral speculations were then to
compensate the poverty of intellectual science. But morality, and even
religion itself, were to be degraded, as little more than technical
terms of a cold and unmeaning logic. The knowledge of our mental frame
was then, indeed, professedly cultivated with most assiduous zeal; and
if much technical phraseology, and much contention, were sufficient
to constitute an elaborate science, that assiduous zeal might well
deserve to have been rewarded with so honourable a name. But what
reasonable hope of a progress truly scientific could be formed, when
to treat of the philosophy of mind was to treat of every thing but of
the mind and its affections; when some of the most important questions,
with respect to it, were, Whether its essence were distinct from its
existence? whether its essence therefore might subsist, when it had no
actual existence? and what were all the qualities inherent in it as a
nonentity? In morals, whether ethics were an art or a science? whether,
if the mind had freedom of choice, this independent _will_ be an entity
or a quiddity? and whether we should say, with a dozen schoolmen, that
virtue is good, because it has intrinsic goodness, or, with a dozen
more, that it has this intrinsic goodness, because it is good?
In natural theology, questions of equal moment were contested with
equal keenness and subtilty; but they related less to the Deity,
of whose nature, transcendent as it is, the whole universe may be
considered as in some degree a faint revelation, than to those
spiritual ministers of his power, of whose very existence nature
affords no evidence, and of whom revelation itself may be said to
teach us little but the mere existence. Whether angels pass from one
point of space to another, without passing through the intermediate
points? whether they can visually discern objects in the dark? whether
more than one can exist at the same moment in the same physical point?
whether they can exist in a perfect vacuum, with any relation to the
absolute incorporeal void? and whether if an angel were in vacuo, the
void could still truly be termed _perfect_?--such, or similar to these
were the great inquiries in that department of Natural Theology, to
which, as to a separate science, was given the name of _Angelography_:
and of the same kind were the principal inquiries with respect to the
Deity himself, not so much an examination of the evidence which nature
affords of his self-existence, and power, and wisdom, and goodness,
those sublime qualities which even our weakness cannot contemplate
without deriving some additional dignity from the very greatness which
it adores, as a solution of more subtile points, whether he exist in
imaginary space as much as in the space that is real? whether he can
cause a mode to exist without a substance? whether, in knowing all
things, he know universals, or only things singular? and whether he
love a possible unexisting angel better than an actually existing
insect?
“Indignandum de isto, non disputandum est.”--“Sed non debuit hoc nobis
esse propositum arguta disserere,[1] et philosophiam in has augustias
ex sua majestate detrahere. Quanto satius est, ire aperta via et
recta, quam sibi ipsi flexus disponere, quos cum magna molestia debeas
relegere?”[2]--“Why waste ourselves,” says the same eloquent moralist;
“why torture and waste ourselves in questions, which there is more real
subtilty in despising than in solving?”--
“Quid te troques et maceras, in ea quæstione quam subtilius est
contempsisse quam solvere?”[3]
From the necessity of such inquiries we are now fortunately freed.
The frivolous solemnities of argument, which, in the disputations of
Scotists and Thomists, and the long controversy of the believers and
rejectors of the universal _a parti rei_, rendered human ignorance so
very proud of its temporary triumphs over human ignorance, at length
are hushed forever; and, so precarious is all that glory, of which
men are the dispensers, that the most subtile works, which for ages
conferred on their authors a reverence more than praise, and almost
worship, would now scarcely find a philosophic adventurer, so bold, as
to avow them for his own.
The progress of intellectual philosophy may indeed, as yet, have
been less considerable than was to be hoped under its present better
auspices. But it is not a little, to have escaped from a labyrinth,
so very intricate, and so very dark, even though we should have done
nothing more than advance into sunshine and an open path, with a long
journey of discovery still before us. We have at last arrived at the
important truth, which now seems so very obvious a one, that the mind
is to be known best by observation of the series of changes which it
presents, and of all the circumstances which precede and follow these;
that, in attempting to explain its phenomena, therefore, we should
know what those phenomena are; and that we might as well attempt to
discover, by logic, unaided by observation or experiment, the various
coloured rays that enter into the composition of a sunbeam, as to
discover, by dialectic subtilties, _a priori_, the various feelings
that enter into the composition of a single thought or passion.
The mind, it is evident, may, like the body to which it is united,
or the material objects which surround it, be considered simply as
a substance possessing certain qualities, susceptible of various
affections or modifications, which, existing successively as momentary
states of the mind, constitute all the phenomena of thought and
feeling. The general circumstances in which these changes of state
succeed each other, or, in other words, the laws of their succession,
may be pointed out, and the phenomena arranged in various classes,
according as they may resemble each other, in the circumstances that
precede or follow them, or in other circumstances of obvious analogy.
There is, in short, a science that may be termed _mental physiology_,
as there is another science relating to the structure and offices of
our corporeal frame, to which the term _physiology_ is more commonly
applied; and as, by observation and experiment, we endeavour to trace
those series of changes which are constantly taking place in our
material part, from the first moment of animation to the moment of
death; so, by observation, and in some measure also by experiment, we
endeavour to trace the series of changes that take place in the mind,
fugitive as these successions are, and rendered doubly perplexing by
the reciprocal combinations into which they flow. The innumerable
changes, corporeal and mental, we reduce, by generalizing, to a few
classes; and we speak, in reference to the mind, of its faculties or
functions of perception, memory, reason, as we speak, in reference to
the body, of its functions of respiration, circulation, nutrition.
This mental physiology, in which the mind is considered simply as a
substance endowed with certain susceptibilities, and variously affected
or modified in consequence, will demand of course our first inquiry;
and I trust that the intellectual analyses, into which we shall be led
by it, will afford results that will repay the labour of persevering
attention, which they may often require from you.
In one very important respect, however, the inquiries, relating to the
physiology of mind, differ from those which relate to the physiology
of our animal frame. If we could render ourselves acquainted with the
intimate structure of our bodily organs, and all the changes which
take place, in the exercise of their various functions, our labour,
with respect to them, might be said to terminate. But though our
intellectual analysis were perfect, so that we could distinguish,
in our most complex thought or emotion, its constituent elements,
and trace with exactness the series of simpler thoughts which have
progressively given rise to them, other inquiries, equally, or still
more important, would remain. We do not know all which is to be known
of the mind, when we know all its phenomena, as we know all which can
be known of matter, when we know the appearances which it presents, in
every situation in which it is possible to place it, and the manner in
which it then acts or is acted upon by other bodies. When we know that
man has certain affections and passions, there still remains the great
inquiry, as to the propriety or impropriety of those passions, and of
the conduct to which they lead. We have to consider, not merely how he
is capable of acting, but also, whether, acting in the manner supposed,
he would be fulfilling a duty or perpetrating a crime. Every enjoyment
which man can confer on man, and every evil, which he can reciprocally
inflict or suffer, thus become objects of two sciences--first of
that intellectual analysis which traces the happiness and misery, in
their various forms and sequence, as mere phenomena or states of the
substance _mind_;--and secondly, of that ethereal judgment, which
measures our approbation and disapprobation, estimating, with more
than judicial scrutiny, not merely what is done, but what is scarcely
thought in secrecy and silence, and discriminating some element of
moral good or evil, in all the physical good and evil, which it is in
our feeble power to execute, or in our still frailer heart, to conceive
and desire.
To this second department of inquiry belong the doctrines of general
_ethics_.
But, though man were truly impressed with the great doctrine of moral
obligation, and truly desirous, in conformity with it, of increasing,
as far as his individual influence may extend, the sum of general
happiness, he may still err in the selection of the means which he
employs for this benevolent purpose. So essential is knowledge, if
not to virtue, at least to all the ends of virtue, that, without it,
benevolence itself, when accompanied with power, may be as destructive
and desolating as intentional tyranny; and notwithstanding the great
principles of progression in human affairs, the whole native vigour of
a state may be kept down for ages, and the comfort, and prosperity,
and active industry of unexisting millions be blasted by regulations,
which, in the intention of their generous projectors, were to stimulate
those very energies which they repressed, and to relieve that very
misery which they rendered irremediable. It therefore becomes an
inquiry of paramount importance, what are the means best calculated for
producing the greatest amount of social good? By what ordinances would
public prosperity, and all the virtues which not merely adorn that
prosperity, but produce it, be most powerfully excited and maintained?
This political department of our science, which is in truth only a
subdivision, though a very important one, of general practical ethics,
comprehends, of course, the inquiries as to the relative advantages
of different forms of government, and the expediency of the various
contrivances which legislative wisdom may have established, or may be
supposed to establish, for the happiness and defence of nations.
The inquiries, to which I have as yet alluded, relate to the mind,
considered simply as an object of physiological investigation; or to
man, considered in his moral relations to a community, capable of
deriving benefit from his virtues and knowledge, or of suffering by his
errors and his crimes. But there is another more important relation in
which the mind is still to be viewed,--that relation which connects
it with the Almighty Being to whom it owes its existence. Is man,
whose frail generations begin and pass away, but one of the links of
an infinite chain of beings like himself, uncaused, and co-eternal
with that self-existing world of which he is the feeble tenant? or,
Is he the offspring of an all creating Power, that adapted him to
nature, and nature to him, formed together with the magnificent scene
of things around him, to enjoy its blessings, and to adore, with the
gratitude of happiness, the wisdom and goodness from which they flow?
What attributes, of a Being so transcendent, may human reason presume
to explore? and, What homage will be most suitable to his immensity,
and our nothingness? Is it only for an existence of a few moments,
in this passing scene, that he has formed us? or, Is there something
within us, over which death has no power,--something, that prolongs
and identifies the consciousness of all which we have done on earth,
and that, after the mortality of the body, may yet be a subject of the
moral government of God? When compared with these questions, even the
sublimest physical inquiries are comparatively insignificant. They
seem to differ, as it has been said, in their relative importance and
dignity, almost as philosophy itself differs from the mechanical arts
that are subservient to it. “Quantum inter philosophiam interest,--et
cæteras artes; tantum interesse existimo in ipsa philosophia, inter
illam partem quæ ad homines et hanc quæ ad Deos spectat. Altior est hæc
et animosior: multum permisit sibi; non fuit oculis contenta. Majus
esse quiddam suspicata est, ac pulchrius, quod extra conspectum natura
posuisset.”[4] It is when ascending to these sublimer objects, that the
mind seems to expand, as if already shaking off its earthly fetters,
and returning to its source; and it is scarcely too much to say,
that the delight which it thus takes in things divine is an internal
evidence of its own divinity. “Cum illa tetigit, alitur, crescit: ac
velut vinculis liberatus, in originem redit. Et hoc habet argumentum
divinitatis suæ, quod illum divina delectant.”
I have thus briefly sketched the various important inquiries, which
the philosophy of mind, in its most extensive sense, may be said to
comprehend. The nature of our spiritual being, as displayed in all
the phenomena of feeling and thought--the ties which bind us to our
fellow-men, and to our Creator--and the prospect of that unfading
existence, of which life is but the first dawning gleam; such are the
great objects to which in the department of your studies committed
to my charge, it will be my office to guide your attention and
curiosity. The short period of the few months to which my course is
necessarily limited, will not, indeed, allow me to prosecute, with such
full investigation as I should wish, every subject that may present
itself in so various a range of inquiry. But even these few months,
I flatter myself, will be sufficient to introduce you to all which
is most important for you to know in the science, and to give such
lights as may enable you, in other hours, to explore, with success,
the prospects that here, perhaps, may only have opened on your view.
It is not, I trust, with the labours of a single season that such
inquiries, on your part, are to terminate. Amid the varied occupations
and varied pleasures of your future years,--in the privacy of domestic
enjoyment, as much as in the busier scenes of active exertion,--the
studies on which you are about to enter must often rise to you again
with something more than mere remembrance; because there is nothing
that can give you interest, in any period or situation of your life,
to which they are not related. The science of mind, is the science of
yourselves; of all who surround you; of every thing which you enjoy or
suffer, or hope or fear: so truly the science of your very being, that
it will be impossible for you to look back on the feelings of a single
hour, without constantly retracing phenomena that have been here, to
a certain extent, the subjects of your analysis and arrangement. The
thoughts and faculties of your own intellectual frame, and all which
you admire as wonderful in the genius of others,--the moral obligation,
which, as obeyed or violated, is ever felt by you with delight or with
remorse,--the virtues, of which you think as often as you think of
those whom you love; and the vices, which you view with abhorrence, or
with pity,--the traces of divine goodness, which never can be absent
from your view, because there is no object in nature which does not
exhibit them,--the feeling of your dependence on the gracious Power
that formed you,--and the anticipation of a state of existence more
lasting than that which is measured by the few beatings of a feeble
pulse,--these in their perpetual recurrence, must often recal to you
the inquiries that, in this place, engaged your early attention. It
will be almost as little possible for you to abandon wholly such
speculations, as to look on the familiar faces of your home with a
forgetfulness of every hour which they have made delightful, or to lose
all remembrance of the very language of your infancy, that is every
moment sounding in your ears.
Though I shall endeavour, therefore, to give as full a view as my
limits will permit of all the objects of inquiry which are to come
before us, it will be my chief wish to awake in you, or to cherish,
a love of these sublime inquiries themselves. There is a philosophic
spirit which is far more valuable than any limited acquirements of
philosophy; and the cultivation of which, therefore, is the most
precious advantage that can be derived from the lessons and studies
of many academic years:--a spirit, which is quick to pursue whatever
is within the reach of human intellect; but which is not less quick
to discern the bounds that limit every human inquiry, and which,
therefore, in seeking much, seeks only what man may learn:--which
knows how to distinguish what is just in itself from what is merely
accredited by illustrious names; adopting a truth which no one has
sanctioned, and rejecting an error of which all approve, with the same
calmness as if no judgment were opposed to its own:--but which, at
the same time, alive, with congenial feeling, to every intellectual
excellence, and candid to the weakness from which no excellence is
wholly privileged, can dissent and confute without triumph, as it
admires without envy; applauding gladly whatever is worthy of applause
in a rival system, and venerating the very genius which it demonstrates
to have erred.
Such is that philosophic temper to which, in the various discussions
that are to occupy us, it will be my principal ambition to form your
minds; with a view not so much to what you are at present, as to what
you are afterwards to become. You are now, indeed, only entering on
a science, of which, by many of you, perhaps, the very elements have
never once been regarded as subjects of speculative inquiry. You
have much, therefore, to learn, even in learning only what others
have thought. But I should be unwilling to regard you as the passive
receivers of a system of opinions, content merely to remember whatever
mixture of truths and errors may have obtained your easy assent.
I cannot but look to you in your maturer character, as yourselves
the philosophers of other years; as those who are, perhaps, to add
to science many of its richest truths, which as yet are latent to
every mind, and to free it from many errors, in which no one has yet
suspected even the possibility of illusion. The spirit which is itself
to become productive in you, is therefore, the spirit which I wish to
cultivate; and happy, as I shall always be, if I succeed in conveying
to you that instruction which it is my duty to communicate, I shall
have still more happiness if I can flatter myself, that, in this very
instruction, I have trained you to habits of thought, which may enable
you to enrich, with your own splendid discoveries, the age in which you
live, and to be yourselves the instructors of all the generations that
are to follow you.
FOOTNOTES:
[1] Argutias serere. Lect. var.
[2] Seneca, Ep. 102.
[3] Ibid, 49.
[4] Seneca Nat. Quæst. Lib. 1. Præf.
LECTURE II.
RELATION OF THE PHILOSOPHY OF MIND TO THE SCIENCES IN GENERAL.
In my former Lecture, Gentlemen, I gave you a slight sketch of
the departments into which the Philosophy of Mind divides itself,
comprehending, in the _first_ place, The physiology of the mind,
considered as a substance capable of the various modifications, or
states, which constitute, as they succeed each other, the phenomena
of thought and feeling; _secondly_, The doctrines of general ethics,
as to the obligation, under which man lies, to increase and extend,
as widely as possible, the happiness of all that live; _thirdly_, The
political doctrines, as to the means which enable him, in society with
his fellow men, to furthermost successfully, and with the least risk
of future evil, that happiness of all, which it is the duty of each
individually to wish and to promote; and, _fourthly_, The doctrines of
natural theology, as to the existence and attributes of that greatest
of Beings, under whose moral government we live, and the foundations
of our confidence that death is only a change of scene, which, with
respect to our mortality indeed, may be said to be its close; but
which, with respect to the soul itself, is only one of the events of a
life that is everlasting.
Of these great divisions of our subject, the _Physiology of the
Mind_, or the consideration of the regular series of phenomena which
it presents, simply as states or affections of the mind, is that to
which we are first to turn our attention. But, before entering on
it, it may be useful to employ a few Lectures in illustrating the
_advantages_, which the study of the mind affords, and the _principles
of philosophizing_, in their peculiar application to it--subjects,
which, though of a general kind, will, I trust, leave an influence that
will be felt in all the particular inquiries in which we are to be
engaged; preparing you, both for appreciating better the importance of
those inquiries, and for prosecuting them with greater success.
One very obvious distinction of the physical investigations of mind
and matter, is, that, in intellectual science, the _materials_ on
which we operate, the _instruments_ with which we operate, and the
_operating agent_, are the same. It is the mind, endowed with the
faculties of perception and judgment, observing, comparing, and
classifying the phenomena of the mind. In the physics of matter, it
is, indeed, the mind which observes, compares, and arranges; but the
phenomena are those of a world, which, though connected with the
mind by many wonderful relations of reciprocal agency, still exists
independently of it--a world that presents its phenomena only in
circumstances, over most of which we have no controul, and over others
a controul that is partial and limited. The comparative facility,
as to all external circumstances, attending the study of the mental
phenomena, is unquestionably an advantage of no small moment. In every
situation in which man can be placed, as long as his intellectual
faculties are unimpaired, it is impossible that he should be deprived
of opportunities of carrying on this intellectual study; because, in
every situation in which he can be placed, he must still have with him
that universe of thought, which is the true home and empire of the
mind. No costly apparatus is requisite--no tedious waiting for seasons
of observation. He has but to look within himself to find the elements
which he has to put together, or the compounds which he has to analyze,
and the instruments that are to perform the analysis or composition.
It was not, however, to point out to you the advantage which arises
to the study of our mental frame, from the comparative facility as
to the circumstances attending it, that I have led your attention to
the difference, in this respect, of the physics of mind and matter.
It was to show,--what is of much more importance,--how essential a
right view of the science of mind is to every other science, even to
those sciences, which superficial thinkers might conceive to have no
connexion with it; and how vain it would be to expect, that any branch
of the physics of mere matter could be cultivated to its highest degree
of accuracy and perfection, without a due acquaintance with the nature
of that intellectual medium, through which alone the phenomena of
matter become visible to us, and of those intellectual instruments, by
which the objects of every science, and of every science alike, are
measured, and divided, and arranged. We might almost as well expect to
form an accurate judgment, as to the figure, and distance, and colour
of an object, at which we look through an optical glass, without paying
any regard to the colour and refractory power of the line itself. The
distinction of the sciences and arts, in the sense in which these words
are commonly understood, is as just as it is familiar; but it may be
truly said, that, in relation to our power of discovery, science is
itself an art, or the result of an art. Whether, in this most beautiful
of processes, we regard the mind as the instrument or the artist, it
is equally that by which all the wonders of speculative, or practical
knowledge, are evolved. It is an agent operating in the production of
new results, and employing for this purpose the known laws of thought,
in the same manner as, on other occasions, it employs the known laws of
matter. The objects, to which it may apply itself, are indeed various,
and, as such, give to the sciences their different names. But, though
the objects vary, the observer and the instrument are continually the
same. The limits of the powers of this mental instrument, are not the
limits of its powers alone; they are also the only real limits, within
which every science is comprehended. To the extent which it allows, all
those sciences, physical or mathematical, and all the arts which depend
on them, may be improved; but, beyond this point, it would be vain to
expect them to pass; or rather, to speak more accurately, the very
supposition of any progress beyond this point would imply the grossest
absurdity; since human science can be nothing more than the result
of the direction of human faculties to particular objects. To the
astronomer, the faculty by which he calculates the disturbing forces
that operate on a satellite of Jupiter, in its revolution round its
primary planet, is as much an instrument of his art, as the telescope
by which he distinguishes that almost invisible orb; and it is as
important, and surely as interesting, to know the real power of the
intellectual instrument, which he uses, not for calculations of this
kind only, but for all the speculative and moral purposes of life, as
it can be to know the exact power of that subordinate instrument, which
he uses only for his occasional survey of the heavens.
To the philosophy of mind, then, every speculation, in every science,
may be said to have relation as to a common centre. The knowledge
of the quality of matter, in the whole wide range of physics, is not
itself a phenomenon of matter, more than the knowledge of any of our
intellectual or moral affections; it is truly, in all its stages of
conjecture, comparison, doubt, belief, a phenomenon of mind; or,
in other words, it is only the mind itself existing in a certain
state. The inanimate bodies around us might, indeed, exhibit the same
changes as at present, though no mind had been created. But science
is not the existence of these inanimate bodies; it is the principle
of thought itself variously modified by them, which, as it exists in
certain states, constitutes that knowledge which we term _Astronomy_;
in certain other states, that knowledge which we term _Chemistry_;
in other states our Physiology, corporeal or mental, and all the
other divisions and subdivisions of science. It would surely be
absurd to suppose, that the mixture of acids and alkalies constitutes
_Chemistry_, or that Astronomy is formed by the revolution of planets
round a sun. Such phenomena, the mere objects of science, are only the
occasions on which Astronomy and Chemistry arise in the mind of the
inquirer, Man. It is the mind which perceives bodies, which reasons
on their apparent relations, which joins them in thought as similar,
however distant they may be in sphere, or separates them in thought
as dissimilar, though apparently contiguous. These perceptions,
reasonings, and classifications of the mind must, of course be
regulated by the laws of mind, which mingle in their joint result
with the laws of matter. It is the object indeed which affects the
mind when sentient; but it is the original susceptibility of the mind
itself, which determines and modifies the particular affection, very
nearly, if I may illustrate what is mental by so coarse an image, as
the impression which a seal leaves on melted wax depends, not on the
qualities of the wax alone, or of the seal alone, but on the softness
of the one, and the form of the other. Change the external object which
affects the mind in any case, and we all know, that the affection of
the mind will be different. It would not be less so, if, without any
change of object, there could be a change in the mere feeling, whatever
it might be, which would result from that different susceptibility
becoming instantly as different, as if not the mind had been altered,
but the object which it perceived. There is no physical science,
therefore, in which the laws of mind are not to be considered together
with the laws of matter; and a change in either set of laws would
equally produce a change in the nature of the science itself.
If, to take one of the simplest of examples, the mind had been formed
susceptible of all the modifications which it admits at present, with
the single exception of those which it receives on the presence of
light, of how many objects and powers in nature, which we are now
capable of distinguishing, must we have remained in absolute ignorance!
But would this comparative ignorance of many objects be the only effect
of such a change of the laws of mind, as I have supposed? Or rather,
is it not equally certain, that this simple change alone would be
sufficient to alter the very nature of the limited science of which the
mind would still be capable, as much as it narrowed its extent? Science
is the classification of relations; varying, too, in every case, as the
relations observed are different; and how very differently should we,
in such circumstances, have classed the few powers of the few objects,
which might still have become known to us, since we could no longer
have classed them according to any of those visual relations, which
are always the most obvious and prominent. It is even, perhaps, an
extravagant supposition, that a race of the blind, unless endowed with
some other sense to compensate the defect of sight, could have acquired
so much command of the common arts of life, or so much science of any
sort, as to preserve themselves in existence. But though all this, by
a very strong license of _supposition_, were taken for granted, it
must surely be admitted, that the knowledge which man could in those
circumstances acquire, would be not merely less in degree, but would be
as truly different from that which his powers at present have reached,
as if the objects of his science, or the laws which regulate them, had
themselves been changed to an extent, at least as great as the supposed
change in the laws of mind. The _astronomy_ of the blind, if the word
might still be used to express a science so very different from the
present, would, in truth, be a sort of _chemistry_. Day and night, the
magnificent and harmonious revolution of season after season, would
be nothing more than periodical changes of temperature in the objects
around; and that great Dispenser of the seasons, the Source of light,
and beauty, and almost of animation, at whose approach nature seems
not merely to awake, but to rise again, as it was at first, from the
darkness of its original chaos, if its separate existence could be at
all inferred, would probably be classed as something similar, though
inferior in power, to that unknown source of heat, which, by a perilous
and almost unknown process, was fearfully piled and kindled on the
household hearth.
So accustomed are we, however, to consider the nature and limits of the
different sciences, as depending on the objects themselves, and not on
the laws of the mind, which classes their relations, that it may be
difficult for you at first to admit the influence of these mere laws
of mind, as modifying general physics, at least to the extent which
I have now stated. But, that a change in the laws of human thought,
whatever influence it might have in altering the very nature and limits
of the physical sciences, would at least affect greatly the state of
their progress, must be immediately evident to those who consider for
a moment on what discovery depends; the progress of science being
obviously nothing more than a series of individual discoveries, and
the number of discoveries varying with the powers of the individual
intellect. The same phenomena which were present to the mind of Newton,
had been present, innumerable times before, not to the understandings
of philosophers only, but to the very senses of the vulgar. Every thing
was the same to him and to them, except the observing and reasoning
mind. To him alone, however, they suggested those striking analogies,
by which on a comparison of all the known circumstances in both, he
ventured to class the force which retains the planets in their orbits,
with that which occasions the fall of a pebble to the earth.
“Have ye not listen'd, while he bound the suns
And planets to their spheres! the unequal task
Of human kind till then. Oft had they roll'd
O'er erring man the year, and oft disgraced
The pride of schools.
----He took his ardent flight
Through the blue infinite; and every star
Which the clear concave of a winter's night
Pours on the eye, or astronomic tube,
Far-stretching, snatches from the dark abyss,
Or such as farther in successive skies
To fancy shine alone, at his approach
Blazed into suns, the living centre each
Of an harmonious system; all combined,
And ruled unerring by that single power,
Which draws the stone projected to the ground.”[5]
It is recorded of this almost superhuman Genius, whose powers and
attainments at once make us proud of our common nature, and humble us
with our disparity, that, in acquiring the Elements of Geometry, he
was able, in a very large proportion of cases, to pass immediately
from Theorem to Theorem, by reading the mere enunciation of each,
perceiving, as it were intuitively, that latent evidence, which others
are obliged slowly to trace through a long series of Propositions.
When the same Theorem was enunciated, or the same simple phenomenon
observed, the successions of thought, in his mind, were thus obviously
different from the successions of thought in other minds; but it is
easy to conceive the original susceptibilities of all minds such, as
exactly to have corresponded with those of the mind of Newton. And if
the minds of all men, from the creation of the world, had been similar
to the mind of Newton, is it possible to conceive, that the state of
any science would have been, at this moment, what it now is, or in any
respect similar to what it now is, though the laws which regulate the
physical changes in the material universe, had continued unaltered, and
no change occurred, but in the simple original susceptibilities of the
mind itself?
The laws of the observing and comparing mind, then, it must be
admitted, have modified, and must always continue to modify, every
science, as truly as the laws of that particular department of nature
of which the phenomena are observed and compared. But, it may be said,
we are Chemists, we are Astronomers, without studying the philosophy of
mind. And true it certainly is, that there are excellent Astronomers,
and excellent Chemists, who have never paid any particular attention
to intellectual philosophy. The general principles of philosophizing,
which a more accurate intellectual philosophy had introduced, have
become familiar to them, without study. But those general principles
are not less the effect of that improved philosophy of mind, any more
than astronomy and chemistry themselves have now a less title to
be considered as sciences,--because, from the general diffusion of
knowledge in society, those who have never professedly studied either
science, are acquainted with many of their most striking truths. It is
gradually, and almost insensibly, that truths diffuse themselves--at
first admired and adopted by a few, who are able to compare the
present with the past, and who gladly own them, as additions to former
knowledge,--from them communicated to a wider circle, who receive them,
without discussion, as if familiar and long known; and at length, in
this widening progress, becoming so nearly universal, as almost to seem
effects of a natural instinctive law of human thought:--like the light,
which we readily ascribe to the sun, as it first flows directly from
him, and forces his image on our sight; but which, when reflected from
object to object, soon ceases to remind us of its origin, and seems
almost to be a part of the very atmosphere which we breathe.
I am aware, that it is not to improvements in the mere philosophy of
mind, that the great reformation in our principles of physical inquiry
is commonly ascribed. Yet it is to this source--certainly at least to
this source chiefly, that I would refer the origin of those better
plans of philosophical investigation which have distinguished with
so many glorious discoveries the age in which we live, and the ages
immediately preceding. When we think of the great genius of Lord Bacon,
and of the influence of his admirable works, we are too apt to forget
the sort of difficulties which his genius must have had to overcome,
and to look back to his rules of philosophizing, as a sort of ultimate
truths, discoverable by the mere perspicacity of his superior mind,
without referring them to those simple views of nature in relation to
our faculties of discovery, from which they were derived. The rules
which he gives us, are rules of physical investigation; and it is very
natural for us, therefore, in estimating their value, to think of
the erroneous physical opinions which preceded them, without paying
sufficient attention to the false theories of intellect, which had
led to those very physical absurdities. Lord Bacon, if he was not the
first who discovered that we were in some degree idolaters, to use his
own metaphor, in our intellectual worship, was certainly the first who
discovered the extent of our idolatry. But we must not forget, that the
temple which he purified, was not the temple of external nature, but
the temple of the mind,--that in its inmost sanctuaries were all the
idols which he overthrew,--and that it was not till these were removed,
and the intellect prepared for the presence of a nobler divinity, that
Truth would deign to unveil herself to adoration;--as in the mysteries
of those Eastern religions, in which the first ceremony for admission
to the worship of the God is the purification of the worshipper.