nutrition, growth and decay. It is evident, besides, that
Aristotle has annexed, so to say, this high privilege to the
mind, as the seat and source of all moral and intellectual
qualities and faculties.



CHAPTER II.

Note 1, p. 64. It is not only correct that the ivord-
ing, &c.] Aristotle 1 makes a definition to be a term
significant of what a thing essentially is, and, thus a defi-
nition may be employed in place of nouns, or one defini-
tion for another; but a noun cannot be accepted as an
adequate definition, since every definition ought to involve
some kind of cause. It is an expression 2 , in fact, which so
explains any term as to distinguish it from all else, as a
boundary line separates fields. Aristotle, again, makes it
to be something laid down (dea-is fnev eV-n) as the arithme-
tician lays down the unit as indivisible, quantitatively
considered; and yet this is no hypothesis, since the unit,

1 Topica, I. 5. i. Analyt. 6. 1.2. 7.
a Trendel. Comment.



CH. II.] NOTES. 251

in itself, is not the same as the unit in relation that is
in combination. The conclusion is the close of a syllogism,
and to be distinguished from description which proceeds
from particulars, and from definition which is a summary
derived from universals. The distinction between these
terms is exemplified in the text by a geometrical figure
if we say that the " quadrature is that by which a rect-
angle with unequal sides is reduced to a square, this is a
definition but a definition bordering on description, as it
gives no account of how the operation is to be performed,
or whether it can be performed at all;" and if we say that
" the quadrature is the finding of a mean proportional,
the definition partakes of the character of an explanation
rather than a description ;" for if there be found " a mean
proportional between any two lines which make a rect-
angular figure, that proportional is the side of the required
square."

Note 2, p. 64. We say . . . that the animate, &c.] Nu-
trition, or the faculty by which matter can identify other
matter with itself and thereby develop and grow is the
rudimental principle of life, and the distinction between
living and inert matter; for inert unlike living matter,
increases in bulk, not through its own agency but, only
by the casual agglomeration of external particles. This
was assumed to be the sole faculty of plants, as Touch was
supposed to be the first and the only sense necessary to
animal existence ; but it may be questioned whether
nutrition and Touch are ever thus found as isolated and



252 NOTES. [BK. n.

independent faculties. Cuvier * also looked upon nutrition
as the characteristic property of living matter; for life
consists, he observes, in the faculty possessed by certain
corporeal combinations of enduring for a time under some
determinate form, of drawing incessantly into their com-
position portions of surrounding substances, and of giving
back to the elements portions of their own substance."

Note 3, p. 66. With respect to some oftJwse faculties,
&c.] It is the purport of this passage to shew that, by
experiment and observation, we may obtain an insight
into the organs and functions of the body; but that, as
the mental faculties do not admit of being so scrutinized,
the investigation of them is, necessarily, obscure and com-
plicated. The distinction between sentient properties and
mental faculties is further exemplified by the lower forms
of animal existence, which continue to live, after having
been divided, in each of the parts; and as each part has
locomotion and manifests feeling, it is assumed that it
must also have imagination (instinct T) and desire. But
nothing at all resembling this can be predicated of the
mind, since, being indiscerptible, it is without parts, and,
so constituted, it cannot be subject to the change or disso-
lution of the body.

Note 4, p. 67. But something very like this has taken
place, &c.] Aristotle 2 is everywhere consistent with what
is advanced here for an animal is defined by him as a

1 Rdgne A nimal, T. i. 1 1 .
* De Part. n. 8. i.



CH. II.] NOTES. 253

being furnished with senses, and, above all, with that
which first is manifested the Touch ; and, elsewhere ', he
says, that every animal, as such, must have some one sense,
since it is by sensibility that we distinguish what is from
what is not an animal. "It is further suggested that
animals may be distinguished, grouped that is, after
sentient and reasoning faculties, and that Zoology may
thus be founded on universal and demonstrable principles.

Note 5, p. 67. As that by which we live and feel.} As
life, that is, implies a body and living principle, so know-
ledge implies faculties and mind; and health the liability
to sickness ; but as Vital Principle is said to be the cause
of life and feeling, it is, as such, a creative energy, and
cannot, therefore, be matter and subject. It cannot, that
is, be a mere faculty or function, or be subject to what is
termed sickness.

Note 6, p. 68. On which account it is happily assumed,
&c.] This is a summary of what had been said concerning
that something, whatever it be, which constitutes a living
body and distinguishes it from inert or inanimate matter ;
and, although very indefinite, it still is all which can be
said concerning it. Aristotle guards against the assump-
tion, as Vital Principle requires for its manifestation
peculiar matter and exact relation, that it may animate
any kind of body, and thus the argument reverts to living
matter and its capability of organism, as the germ, so to
say, of animal existence. This necessary relation between
1 De Senxu ct Sens. I. 6. 7.



254 NOTES. [BK. n.

the matter and principle is then advanced to refute the
doctrine of metempsychosis maintained by the followers
of Pythagoras ; as the active and passive, the agent and
subject, cannot possibly be mere casual associations. The
subject is further exemplified, in the closing paragraphs,
by those two conditions which pervade all Aristotle's
writings the body while yet in potentiality is, by the
Vital Principle, realised, converted, that is into reality ;
for Vital Principle can act only upon what is in poten-
tiality, and capable, under its influence, with form, of
becoming a specific creature.



CHAPTER III.

Note 1, p. 71. And all animals, without exception,
have the sense of Touch, &c.] Aristotle, having observed
that plants have only the function of nutrition, that is,
are not sentient, proceeds to the first and, therefore, most
universal of the senses that which may, as he assumed,
be present without any other, although there can be no
other without it. Thus, the Touch, as perceptive of food,
was supposed to be subservient to the appetite, and the
Taste, as discriminating, by tangible qualities, what in
food may be genial or otherwise, was held to be a modi-
fication of the Touch ; but the Touch alone was by
Aristotle regarded as distinctive of animal in contrast



CH. III.] NOTES. 255

with vegetable existence. " According to the argument 1 ,
he adds, by which appetite is said to be the mediate cause
of motion, there must, in living animal bodies, be some
such medium ; and the being, therefore, which by its
nature is incapable of motion, is impressionable by
appetite, through some other faculty." Plants, that is,
are not affected by the appetitive stimulus as are
animals.

Note 2, p. 72. As, however, we shall be more explicit,
<fcc.] The Touch being the earliest, so to say, of the
senses and distinctive of animal existence, is here held to
be the cause of appetite, as appetite is of motion ; and
as has been observed, the Touch was supposed to exist
independently of the other senses. This sense is said to
be especially discriminative of food, as animals are
nourished by substances which are hot and cold, dry
and moist, and these qualities are subject to it ; but it
can distinguish only by chance such other properties
(odour, colour, sound, for instance) as do not contribute to
nutrition. It is not easy to attach a definite notion to
the imagination here alluded to, but as Aristotle has
elsewhere distinguished the rational from the sentient
imagination, and as instinct only can be assigned to
creatures with one sense, it may be assumed that this is
its meaning.

Note 3, p. 72. It is clear, then, that there can be but
one, &c.] The triangle 8 forms all rectilineal figures,
1 De Matu An. 10. i. * Saint ffilaire.



256 NOTES. [BK. n.

which have more than three sides, that is, " all such
figures may be divided into triangles, as the square into
two, the pentagon into three, the hexagon into four, &c. ;
and geometry has, since that age, reduced this to a special
theorem."

Note 4, p. 73. Thus, tJte inquiry must, <fec.] The
conclusion here arrived at enforces the necessity of
attention to individual existences, in order to ascertain
what may be the distinction, if such there be, between
Vital Principles ; so that the question reverts to former
speculations, whether or not there is but one Principle
variously imparted, or whether rather, each genus of being
has its own special cause of vitality and motion. It belongs,
also, perhaps, to the same speculation, to ascertain why
beings have been ranged in a series why, that is, such
manifold gradations of existence from man down to the
zoophyte ; unless, indeed, with other conditions of similar
character, it is beyond the pale of human inquiry.

Note 5, p. 73. But to such as possess some one only of
tJie faculties, &c.] It is far from easy to fix upon the exact
equivalents of the original terms (XoyMr/tov, 3a'i/oia, ^ai/ra-
<r('a,) which have been here rendered by calculation, judg-
ment and imagination; but the speculative intellect, (0e-
ptlTiKo*: vovs,') implies it may "be assumed" the human
mind or understanding, which was said to be impassive,
homogeneous, and distinct from all else. It might well,
therefore, be regarded as foreign to an inquiry, the
purport of which is to detect the animating principle



CH. IV.] NOTES. 257

of bodies fitted for receiving its influences. It is some-
what strange that Aristotle, whose teaching was so
didactic, should nowhere have given a definition of that
principle or being, to which he has assigned so exalted a
destiny.



CHAPTER IV.

Note 1, p. 77. But since such beings cannot, <fec.]
The purport of this passage is almost too obvious for
comment, embodying the great fact of the perpetuation
of the species, and compensation, by reproduction, for the
death of the individuals ; and number refers, of course, to
individuals, species to the aggregate.

Note 2, p. 78. The term final cause, &c.] This is a
kind of parenthetical clause, intended merely to guard
against the supposition that the fact of some animals
having a fixed habitat, not being locomotive that is, was
unknown, or had escaped notice.

Note 3, p. 78. And this applies equally to growth and
decay.] Aristotle 1 perceived, although it may be in-
distinctly, that the source of nutrition is through the
blood he perceived, that is, that " the blood is replenished
by vessels, which arise on and are spread over the mesen-
tery, and which empty themselves into the cava and the
1 De Part. Animalm, IV. 3. 4.

17



258 NOTES. [UK. n.

aorta;" the anatomy is, no doubt, imperfect, but it still
is an outline of the knowledge of the lacteals. It seems
to shew that veins gather fluid from the intestines, and
convey it to the large blood vessels ; but there was no
analogous knowledge, in that age, whereby the process of
decay that is absorption could be accounted for. The
term decay, therefore, was the mere expression for a
general fact.

The objection to the terms " upwards and downwards,"
used by Empedocles to delineate the growth of plants,
suggests the advantage that would accrue to science, if its
terms were made sufficiently precise to fix, beyond doubt,
the several relations and positions of the same body, or
all bodies. And in the analogy between the heads of
animals and roots of trees, we cannot but perceive the
outline of a doctrine which has been developed, by modern
science, into homologous physiology.

Note 4, p. 79. The nature of fire seems to some
philosophers, &c.] This is an argument, drawn from the
agency of fire, to dispi-ove the then prevailing opinion,
that, as it alone of the elements appears to be nourished
and to grow, it may be the source of life and the origin
of living actions ; as they are shewn, by the contrast
between living and igneous properties, to be essentially
distinct from one another. The opinion may have
originated from the fact that heat accompanies digestion,
and as fire was by some held to be the first element, it
was readily supposed to be the agent in that process. As



CH. IV.] NOTES. 259

an illustration of this opinion, it was maintained, even by
Aristotle l , that " food, taken into its appointed receptacles,
is vaporised and transmitted to the veins, in which,
undergoing change, it is converted into blood, and car-
ried onward to the heart."

Note 5, p. 81. T/tere are here three things, <fec.] The
meaning of this passage, apart from its scientific wording,
is sufficiently obvious that which nourishes is food when
digested; for food both acts and is acted upon by the
body, and, when so acted upon, it is assimilated to and
incorporated with its substance, through the blood. But
food, being dead, is contrary to the living matter, which
has, however, power to convert it into like, to assimilate
it, that is, to the living system. Thus, food, in its first
state, is contrary to or unlike, and in its last, or concocted
state, it is like the body ; and, therefore, the same element
is in one sense contrary, and in another sense like, acting
upon a contrary or like. So too the rudder, which directs
the vessel, represents the stomach, which converts the
food into nourishment for the body; and the sensibility,
which gives power to the stomach, represents the hand
which, through the rudder, directs the motion of the
vessel ; and the vessel is analogous to the body which
is nourished.

1 De Somno, 3. 3.



17-



260 NOTES. [BK. ir.



CHAPTER V.

Note 1, p. 84. In our treatises upon action and im-
pression, &c.] Some commentators have, in the treatises
here alluded to, seen only a reference to other disquisitions,
as those upon " ' reproduction and destruction,' or decay,"
7rfp\ yei/co-coK KU\ <j)0opd<: ; but as the passages which are
cited do not meet the whole question, it has been suggested
by Trendelenberg that the allusion may be to some other
work which has not come down to us.

Note 2, p. 84. It is difficult to understand, &c.] In
another chapter of this treatise, Aristotle has alluded to
the power possessed by the senses of recalling former
impressions ; of realizing images at will, that is, without
external objects. But the question here is to learn why
the senses, which were supposed to be derived from the
elements, from which or the accidents of which sensation
itself was derived, are not in constant activity. The
answer is, that the normal state, so to say, of the sensi-
bility is potentiality, and that it is insusceptible, there-
fore, of perception, without impression by something
from without to call it into action ; just as the combustible
material requires, in order to burn, the agency of fire.
But the comparison contains a converse proposition, as
while the material is required for the sensibility, it \sfire,



CH. V.] NOTES. 261

which may be regarded as the sensibility, which is required
for the material.

Note 3, p. 84. Since we speak of sentient perception,
&c.] These passages upon perception aud sensation, which,
in themselves, when deeply inquired into, are sufficiently
obscure, are still less, if possible, apprehensible, on account
of the wording and the attempted illustration by the
leading terms, potentiality and reality. It is obvious,
however, that we may and do speak of an individual as
one who hears and sees, whether or not, at the moment,
conscious of sound or colour ; whether that is, awake or
asleep, active or quiescent, in potentiality or reality.
But an individual is, strictly speaking, only then seeing
and hearing when he is actually sensible of colours and
sounds ; just as an individual, to use Aristotle's analogy,
is only then to be accounted really learned, when actually
reflecting upon and exercising some one special subject of
knowledge. All attempts, however, to scrutinize the in-
timate operations, so to speak, of the sensibility under
impression from without or excitation from within soon
lose, even with the advanced knowledge of this age, the
character of inductive science, and are lost, as in the
text, in the maze of metaphysical abstractions. It seems
to be the object of the argument to prove, that the sensi-
bility, before being acted upon by external objects, such as
light, sound, colour, <fec., exists in potentiality and is unlike;
when acted upon, it is raised to the state of reality, and
thus made like to that by which the impression is made.



262 NOTES. [BK. n.

Note 4, p. 85. Before proceeding further let us, &c.]
Tliis and the following passages are but repetitions of
what had been said, and further attempts at elucidation ;
they all too depend for a meaning upon the two great
leading terms. For motion is in a two-fold state when
generated by impulse from without it is passive, when
self-generated it is active ; and that may be regarded
as potential, this as real. Thus, if a body be at rest,
l>efore being impelled, the agent, by which it is im-
pelled, is unlike and active; but, when so moved, it is,
by the very act of motion, made active, and like to the
agent.

Note 5, p. 85. But we must draw a distinction, &c.]
These passages embody, in examples, the two terms so
often alluded to, and exhibit the opposite conditions of
human beings every man is learned, potentially, because
man is naturally so constituted as to be able to become
learned, or, being learned, is subject to an eclipse of his
learning by sleep, or disease, or inattention; and every
man, endowed with the faculties of his nature, may
acquire some one branch of learning, and, when there is
no impediment to his doing so, by the exercise of that
knowledge, become learned in reality.

The individual who is learned in the first sense cannot,
without a succession of changes, (while passing, that is,
from ignorance to knowledge), become, at will, learned, in
reality ; and he can, therefore, be accounted learned, only
in potentiality.



CH. V.] NOTES. 263

Note 6, p. 86. The term impression, <fec.] The same
mode of illustration, through those two terms, is still
continued impression may be to an extent to destroy
sensibility, and obliterate, of course, sensation, or it may
be to that genial extent which raises, so to say, potentiality
to reality, and renders the being conscious of external
objects. So an individual, with knowledge yet potential,
that is, possessed but not exercised, can, by reflecting
upon it, without any change being wrought, render it
a reality ; for the possession of knowledge, like the endow-
ment of sensibility, implies the self-same two-fold condi-
tion. Thus, the state of reflection is to acquired
knowledge what external impressions are to sensibility ;
for, in either case, the agencies, when genial, occasion the
transition from potentiality to reality ; and so eliminate
practical knowledge or perfect consciousness.

Note 7, p. 87. Thefrrst change, however, of this kind,
&c.] It is not easy to perceive how this nascent condition
can be a change, unless the first germ of being may be
so regarded ; and, indeed, it may be supposed, from the
first moment, to have already, in potentiality, the powers
which are yet to be developed. It may be, too, that this
mysterious entity, along with the faculties and powers of
its own nature, may involve the idiosyncrasy of the
parent, for good or for ill ; which was indeed exemplified
in the life and death of the philosophical Montaigne 1 .

1 T. n. chap. 37.



264 NOTES. [BK. n.

This capacity of the system for retaining dormant within
it a something to be developed, by iinknown causes, in
time, is exemplified in the atom of virus, which, after an
indefinite period, may, by mysterious agency, become a
reality in the form of Hydrophobia. Well might the
philosopher, when reflecting upon these incidents, exclaim,
" Qui m'eclaircera de ce progres, je le croirai d'autant
d'autres miracles qu'il voudra."

Note 8, p. 86. So tliat the process by which an indi-
vidual, &c.] This very obscure passage seems to intimate
that, as instruction is only the development of faculties
pre-existing and in potentiality, it is not to be regarded as
an impression; for such an opinion would imply, instead
of nature's ordinary process (development), a change
from a privative state (ignorance), as well as change in
habits of thought. This cannot, however, be insisted
xipon with much confidence ; the French version is, " Done,
ce qui fait passer 1'etre qui est en puissance a la realite
parfaite, & 1'entelechie, en fait d'intelligence et de pensee,
doit s'appeller, non du nom d'apprentissage, mais d'un
tout autre nom."

Note 9, p. 87. There is an analogy between, &c.]
Sensation, that is, is to the body what reflection is to the
mind, save that the one is produced by impression from
without, and, therefore, not subject to the will, while the
latter is the operation of will upon internal faculties.
Thus, sensation admits a series of individual impressions
which are to be analyzed and compared by the mental



CH. VI.] NOTES. 265

operation ; and as the former becomes the parent of
inductive, the latter is the source of deductive science.

Note 10, p. 88. Let it for the present suffice, &a] An
obvious distinction of potentiality a boy is, potentially,
qualified to be a general ; that is, he has, by nature,
faculties and powers which, when developed, will fit him
for the office ; and so is one who, although of suitable age,
and whose faculties and powers are developed, may not
yet have acquired the necessary military knowledge. An
analogous distinction may be traced in sentient properties,
but it is too evanescent for precise description; and the
closing paragraph is a kind of summary of the conversion
of the potential and unlike into the real and like.



CHAPTER VL

Note 1, p. 90. The Touch indeed, &c.] This sense
has a wider range of perception than any other that is,
it is not restricted, like the Sight, Hearing, and Smell, to a
definite organism and one mode of impression ; and, besides
being extended over the body, it is essential to animal
existence. The text makes no allusion to the Taste, be-
cause this sense was regarded 1 as subsidiary to or a modi-
fication of the Touch. The special senses are Sight, Hearing,
and Smell ; Taste is less definite, as the tongue is sensible
1 De Semu et Sent. iv. i.



266 NOTES. [BK. n.

of tangible as well as sapid qualities ; and Touch is ex-
tended over the body. Some properties, however, wliich
are enumerated, are subject to all the senses, and, hence,
termed common; but the attempted illustration of them
by "a kind of motion" (K/W/O-K TJS) does not, owing to its
vagueness, assist in explaining them.

Note 2, p. 91. An object is said to be perceived, <fec.]
An example in illustration of casual or accidental percep-
tion; but it is by its wording so obscure as to stand itself
in need of elucidation. The purport, however, seems to be,
that the percipient does not, by sight, (as sight distinguishes
only colour and form) discern what the white object really
is ; but the other senses, by some accidental perception,
coming in aid of the special sense, may determine that
the white object is a certain individual. There may
besides, perhaps, be a covert allusion to the two-fold
acceptation of the term accident, which signified then
as it does now both casual incidents and the real, or
inalienable properties of bodies ; and if so, the passage
may imply that the individual is perceived by chance;
detected, that is, by a mere guess. It is of little moment,
but the individual alluded to is said, by Philoponus, to
have been a friend of Aristotle's ; and that letters which
had passed between them were extant in his time.



CH. VII.] NOTES. 267



CHAPTER VII.

Note 1, p. 93. TJie visible is colour, &c.] Aristotle 1
says that the faculty of Sight announces to us, dis-