282 
SCIENCE. 
There is a profound difference between creatures in which 
one only of these voices speaks, and man, whose ears 
are, as it were, open to them both. The things which 
we do in obedience to the lower and simpler voice are 
indeed many, various, and full of a true and wonderful 
significance. But the things which we do and the 
affections which we cherish, in obedience to the higher 
voice have a rank, a meaning, and a scope which is all 
their own. There is no indication in the lower animals 
of this double Personality. They hear no voice but one : 
and the whole law of their Being is perfectly fulfilled in fol- 
lowing it. This it is which gives its restfulness to Nature, 
whose abodes are indeed what Wordsworth calls them — 
” Abodes where Self-disturbance hath no part.” 
On the other hand, the double Personality, the presence of 
“ Two Voices,” is never wholly wanting even in the most 
degraded of human beings— their thoughts everywhere “ac- 
cusing or else excusing one another.” 
Knowing, therefore, in ourselves both these kinds of op- 
eration, we can measure the distance between them, and we 
can thoroughly understand how animals may be able to do 
all that they actually perform, without ever passing through 
the processes of augmentation by which we reach the con- 
clusions of conscious reason and of moral obligation. More- 
over, seeing and feeling the difference, we can see and feel 
the relations which obtain between the two classes of men- 
tal work. The plain truth is, that the higher and more 
complicated work is done, and can only be done in this 
life, with the material supplied by the lower and simpler 
tools. Nay, more, the very highest and most aspiring men- 
tal processes rest upon the lower, as a building rests upon 
its foundation stones. They are like the rude but massive 
substructions from which some great temple springs. Not 
only is the impulse, the disposition, and the ability to rea- 
son as purely intuitive and congenital in Man as the disposi- 
tion to eat, but the fundamental axioms on which all reason- 
ing rests are, and can only be, intuitively perceived. This, 
indeed, is the essential character of all the axioms or self- 
evident propositions which are the basis of reasoning, that 
the truth of them is perceived by an act of apprehension, 
which, if it depends on any process, depends on a process 
unconscious, involuntary, and purely automatic. But this 
is the definition, the only definition', of instinct, or intuition. 
All conscious reasoning thus starts from the data which this 
great faculty supplies ; and all our trust and confidence in 
the results of reasoning must depend on our trust and confi- 
dence in the adjusted harmony which has been established 
between instinct and the truths of nature. Not only is the 
idea of mechanism consistent with this confidence, but it is 
inseparable from it. No firmer gronnd for that confidence 
can be given us in thought than this conception — that as the 
eye of sense is a mechanism specially adjusted to receive 
the light of heaven, so is the mental eye a mechanism 
specially adjusted to perceive those realities which are 
in the nature of necessary and eternal truth. More- 
over, the same conception helps us to understand 
the real nature of those limitations upon our faculties 
which curtail their range, and which yet, in a sense, we may 
be said partially to overpass in the very act of becoming 
conscious of them. We see it to be a great law prevailing 
in the instincts of the lower animals, and in our own, that 
they are true not only as guiding the animal rightly to the 
satisfaction of whatever appetite is immediately concerned, 
but true also as ministering to ends of which the animal 
knows nothing, although they are ends of the highest im- 
portance, both in its own economy and in the far-off econ- 
omies of creation. In direct proportion as our own minds 
and intellects partake of the same nature, and are founded 
on the same principle of adjustment, we may feel assured 
that the same law prevails in their nobler work and func- 
tions. And the glorious law is no less than this — that the 
work of instinct is true not only for the short way it goes, 
but for that infinite distance into which it leads in a true di- 
rection. 
I know no argument better fitted than this to dispel the 
sickly dreams, the morbid misgivings, of the Agnostic. 
Nor do I know of any other conception as securely founded 
on science, properly so called, which better serves to render 
intellig He and to bring within the familiar analogies of 
Nature t‘ ose higher and rarer mental gifts which we know 
as genius, and even that highest and rarest of all which we 
understand as inspiration. That the human mind is always 
in some degree, and that certain individual minds have 
been in a special degree, reflecting surfaces, as it were, for 
the verities of the unseen and eternal world, is a concep- 
tion having all the characters of coherence which assure 
us of its harmony with the general constitution and the 
common course of things. 
And so this doctrine of animal automatism — the notion 
that the mind of man is indeed a structure and a mechan- 
ism — a notion which is held over our heads as a terror and 
a doubt — becomes, when closely scrutinized, the most com- 
forting and re-assuring of all conceptions. No stronger 
assurance can be given us that our faculties, when rightly 
used, are powers on which we can indeed rely. It reveals 
what may be called the strong physical foundations on 
which the truthfulness of Reason rests. And more than 
this — it clothes with the like character of trustworthiness 
every instinctive and intuitive affection of the human soul. 
It roots the reasonableness of faith in our conviction of the 
Unities of Nature. It tells us that as we know the instincts 
of the lower animals to be the index and the result of laws 
which are out of sight to them, so also have our own 
higher instincts the same relation to truths which are of 
corresponding dignity and of corresponding scope. 
Nor can this conception of the mind of Man being 
connected with an adjusted mechanism cast, as has been 
suggested, any doubt on the freedom of the Will, — 
such as by the direct evidence of consciousness we 
know that freedom to be. This suggestion is simply a 
repetition of the same inveterate confusion of thought 
which has been exposed before. The question of what 
our powers are is in no way affected by the admis- 
sion or discovery that they are all connected with an 
apparatus. Consciousness does not tell us that we stand 
unrelated to the system of things of which we form a 
part. We dream — or rather we simply rave — if we think 
we are free to choose among things which are not presented 
to our choice,— or if we think that choice itself can be free 
from motives, — or if we think that we can find any motive 
outstde the number of those to which by the structure of 
our minds and of its organ we have been made accessible. 
The only freedom of which we are really conscious is free- 
dom from compulsion in choosing among things which are 
presented to our choice, — consciousness also attesting the 
fact that among those things some are coincident, and some 
are not coincident, with acknowledged obligation. This, 
and all other direct perceptions, are not weakened but con- 
firmed by the doctrine that our minds are connected with 
an adjusted mechanism. Because the first result of this 
conception is to establish the evidence of conscious- 
ness when given under healthy conditions, and when prop- 
erly ascertained, as necessarily the best and the nearest 
representation of the truth. This it does in recognizing 
ourselves, and all the faculties we possess, to be nothing 
but the result and index of an adjustment contrived by 
and reflecting the Mind which is supreme in Nature. We 
are derived and not original. We have been created, or — 
if any one likes the phrase better — we have been “evolv- 
ed : ” not, however, out of nothing, nor out of confusion, 
nor out of lies, — but out of “ Nature,” which is but a word 
for the sum of all existence — the source of all order, and 
the very ground of all truth — the fountain in which all full- 
ness dwells. 
ASTRONOMICAL NOTES. 
ON THE DETERMINATION OF THE VALUE OF ONE 
REVOLUTION OF A MICROMETER SCREW, ETC. 
To determine the value of a revolution of a micrometer 
screw, it is desirable to use several different methods. 
The most common and least accurate is by the observa- 
tion of the transits of stars over two wires of the microme- 
ter, set at a known distance (in revolutions) apart. Me- 
chanical measures, depending upon the measurement of 
the length of the screw, of the dimensions of the object- 
ive, and of the principal focal length of the telescope come 
next. The measures in arc of terrestrial objects of known 
linear dimensions come next. Bessel’s triangulation of 
