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| I CAN easily
conceive, most Holy Father, that as soon as some people learn that in
this book which I have written concerning the revolutions of the
heavenly bodies, I ascribe certain motions to the Earth, they will cry
out at once that I and my theory should be rejected. For I am not so
much in love with my conclusions as not to weigh what others will think
about them, and although I know that the meditations of a philosopher
are far removed from the judgment of the laity, because his endeavor is
to seek out the truth in all things, so far as this is permitted by God
to the human reason, I still believe that one must avoid theories
altogether foreign to orthodoxy. Accordingly, when I considered in my
own mind how absurd a performance it must seem to those who know that
the judgment of many centuries has approved the view that the Earth
remains fixed as center in the midst of the heavens, if I should, on the
contrary, assert that the Earth moves; I was for a long time at a loss
to know whether I should publish the commentaries which I have written
in proof of its motion, or whether it were not better to follow the
example of the Pythagoreans and of some others, who were accustomed to
transmit the secrets of Philosophy not in writing but orally, and only
to their relatives and friends, as the letter from Lysis to Hipparchus
bears witness. They did this, it seems to me, not as some think, because
of a certain selfish reluctance to give their views to the world, but in
order that the noblest truths, worked out by the careful study of great
men, should not be despised by those who are vexed at the idea of taking
great pains with any forms of literature except such as would be
profitable, or by those who, if they are driven to the study of
Philosophy for its own sake by the admonitions and the example of
others, nevertheless, on account of their stupidity, hold a place among
philosophers similar to that of drones among bees. Therefore, when I
considered this carefully, the contempt which I had to fear because of
the novelty and apparent absurdity of my view, nearly induced me to
abandon utterly the work I had begun. |
1 |
| My friends, however, in spite of long delay and even
resistance on my part, withheld me from this decision. First among these
was Nicolaus Schonberg, Cardinal of Capua, distinguished in all branches
of learning. Next to him comes my very dear friend, Tidemann Giese,
Bishop of Culm, a most earnest student, as he is, of sacred and, indeed,
of all good learning. The latter has often urged me, at times even
spurring me on with reproaches, to publish and at last bring to the
light the book which had lain in my study not nine years merely, but
already going on four times nine. Not a few other very eminent and
scholarly men made the same request, urging that I should no longer
through fear refuse to give out my work for the common benefit of
students of Mathematics. They said I should find that the more absurd
most men now thought this theory of mine concerning the motion of the
Earth, the more admiration and gratitude it would command after they saw
in the publication of my commentaries the mist of absurdity cleared away
by most transparent proofs. So, influenced by these advisors and this
hope, I have at length allowed my friends to publish the work, as they
had long besought me to do. |
2 |
| But perhaps Your Holiness will not so much wonder that I
have ventured to publish these studies of mine, after having taken such
pains in elaborating them that I have not hesitated to commit to writing
my views of the motion of the Earth, as you will be curious to hear how
it occurred to me to venture, contrary to the accepted view of
mathematicians, and well-nigh contrary to common sense, to form a
conception of any terrestrial motion whatsoever. Therefore I would not
have it unknown to Your Holiness, that the only thing which induced me
to look for another way of reckoning the movements of the heavenly
bodies was that I knew that mathematicians by no means agree in their
investigations thereof. For, in the first place, they are so much in
doubt concerning the motion of the sun and the moon, that they can not
even demonstrate and prove by observation the constant length of a
complete year; and in the second place, in determining the motions both
of these and of the five other planets, they fail to employ consistently
one set of first principles and hypotheses, but use methods of proof
based only upon the apparent revolutions and motions. For some employ
concentric circles only; others, eccentric circles and epicycles; and
even by these means they do not completely attain the desired end. For,
although those who have depended upon concentric circles have shown that
certain diverse motions can be deduced from these, yet they have not
succeeded thereby in laying down any sure principle, corresponding
indisputably to the phenomena. These, on the other hand, who have
devised systems of eccentric circles, although they seem in great part
to have solved the apparent movements by calculations which by these
eccentrics are made to fit, have nevertheless introduced many things
which seem to contradict the first principles of the uniformity of
motion. Nor have they been able to discover or calculate from these the
main point, which is the shape of the world and the fixed symmetry of
its parts; but their procedure has been as if someone were to collect
hands, feet, a head, and other members from various places, all very
fine in themselves, but not proportionate to one body, and no single one
corresponding in its turn to the others, so that a monster rather than a
man would be formed from them. Thus in their process of demonstration
which they term a “method,” they are found to have omitted something
essential, or to have included something foreign and not pertaining to
the matter in hand. This certainly would never have happened to them if
they had followed fixed principles; for if the hypotheses they assumed
were not false, all that resulted there from would be verified
indubitably. Those things which I am saying now may be obscure, yet they
will be made clearer in their proper place. |
3 |
| Therefore, having turned over in my mind for a long time
this uncertainty of the traditional mathematical methods of calculating
the motions of the celestial bodies, I began to grow disgusted that no
more consistent scheme of the movements of the mechanism of the
universe, set up for our benefit by that best and most law abiding
Architect of all things, was agreed upon by philosophers who otherwise
investigate so carefully the most minute details of this world.
Wherefore I undertook the task of rereading the books of all the
philosophers I could get access to, to see whether any one ever was of
the opinion that the motions of the celestial bodies were other than
those postulated by the men who taught mathematics in the schools. and I
found first, indeed, in Cicero, that Niceta perceived that the Earth
moved; and afterward in Plutarch I found that some others were of this
opinion, whose words I have seen fit to quote here, that they may be
accessible to all:— |
4 |
| “Some maintain that the Earth is stationary, but
Philolaus the Pythagorean says that it revolves in a circle about the
fire of the ecliptic, like the sun and moon. Heraklides of Pontus and
Ekphantus the Pythagorean make the Earth move, not changing its
position, however, confined in its falling and rising around its own
center in the manner of a wheel.” |
5 |
| Taking this as a starting point, I began to consider the
mobility of the Earth; and although the idea seemed absurd, yet because
I knew that the liberty had been granted to others before me to
postulate all sorts of little circles for explaining the phenomena of
the stars, I thought I also might easily be permitted to try whether by
postulating some motion of the Earth, more reliable conclusions could be
reached regarding the revolution of the heavenly bodies, than those of
my predecessors. |
6 |
| And so, after postulating movements, which, farther on in
the book, I ascribe to the Earth, I have found by many and long
observations that if the movements of the other planets are assumed for
the circular motion of the Earth and are substituted for the revolution
of each star, not only do their phenomena follow logically therefrom,
but the relative positions and magnitudes both of the stars and all
their orbits, and of the heavens themselves, become so closely related
that in none of its parts can anything be changed without causing
confusion in the other parts and in the whole universe. Therefore, in
the course of the work I have followed this plan: I describe in the
first book all the positions of the orbits together with the movements
which I ascribe to the Earth, in order that this book might contain, as
it were, the general scheme of the universe. Thereafter in the remaining
books, I set forth the motions of the other stars and of all their
orbits together with the movement of the Earth, in order that one may
see from this to what extent the movements and appearances of the other
stars and their orbits can be saved, if they are transferred to the
movement of the Earth. Nor do I doubt that ingenious and learned
mathematicians will sustain me, if they are willing to recognize and
weigh, not superficially, but with that thoroughness which Philosophy
demands above all things, those matters which have been adduced by me in
this work to demonstrate these theories. In order, however, that both
the learned and the unlearned equally may see that I do not avoid
anyone’s judgment, I have preferred to dedicate these lucubrations of
mine to Your Holiness rather than to any other, because, even in this
remote corner of the world where I live, you are considered to be the
most eminent man in dignity of rank and in love of all learning and even
of mathematics, so that by your authority and judgment you can easily
suppress the bites of slanderers, albeit the proverb hath it that there
is no remedy for the bite of a sycophant. If perchance there shall be
idle talkers, who, though they are ignorant of all mathematical
sciences, nevertheless assume the right to pass judgment on these
things, and if they should dare to criticise and attack this theory of
mine because of some passage of Scripture which they have falsely
distorted for their own purpose, I care not at all; I will even despise
their judgment as foolish. For it is not unknown that Lactantius,
otherwise a famous writer but a poor mathematician, speaks most
childishly of the shape of the Earth when he makes fun of those who said
that the Earth has the form of a sphere. It should not seem strange then
to zealous students, if some such people shall ridicule us also.
Mathematics are written for mathematicians, to whom, if my opinion does
not deceive me, our labors will seem to contribute something to the
ecclesiastical state whose chief office Your Holiness now occupies; for
when not so very long ago, under Leo X, in the Lateran Council the
question of revising the ecclesiastical calendar was discussed, it then
remained unsettled, simply because the length of the years and months,
and the motions of the sun and moon were held to have been not yet
sufficiently determined. Since that time, I have given my attention to
observing these more accurately, urged on by a very distinguished man,
Paul, Bishop of Fossombrone, who at that time had charge of the matter.
But what I may have accomplished herein I leave to the judgment of Your
Holiness in particular, and to that of all other learned mathematicians;
and lest I seem to Your Holiness to promise more regarding the
usefulness of the work than I can perform, I now pass to the work
itself. |