Importuned by the Nolan as well as the others, that he should leave aside questions of why, how, and what, Nundinio submitted some argument
-PRU. Per quomodo, et quare; quilibet asinus novit
disputare [With how's and why's, each ass knows how to vie].
THE. - at the end of which he made the point that fills all pamphlets, namely, that if the earth were carried in the direction called east; it would be necessary that the clouds in the air should always appear moving toward west, because of the extremely rapid and fast motion of that globe, which in the span of twenty-four hours must
complete such a great revolution [71. This objection is considered by Copernicus, to say nothing of earlier sources. Nothing is added by Bruno's dicta to Copernicus' solution except the organismic phraseology. ] To that the Nolan replied that this air through which the clouds and winds move are parts of the earth, because he wants (as the proposition demands) to mean under the name of earth the whole machinery and the entire animated part, which consists of dissimilar [variegated] parts; so that the rivers, the rocks, the seas, the whole vaporous and turbulent air, which is enclosed within the highest moutains, should belong to the earth as its members, just as the air [does] in the lungs and in other cavities of animals by which they breathe, widen their arteries, and other similar effects necessary for life are performed. The clouds, too, move through accidents [happenings] in the body of the earth and are [based] in its bowels as are the waters. This is so stated by Aristotle in the first book of the Meteors[72. Typically enough, Bruno's organismic analogy is from Aristotle's Meleorologica, the only book of Aristotle which Bruno quotes at length and with approval, Undoubtedly because of its virulent animism and because of its sections on cyclic processes. That Bruno failed to see the Meleorologica in its true unscientific light is one more indication of the peculiar character of Bruno's science. By 1585 several sections of the Meleorologica had been the target of sharp denounciations. ] where he says that this air which is around the earth and is humid and hot [cold] because of the earth's exhalations, is surrounded by another air, dry and hot, and no clouds can be found there:
and that this air is outside the circumference of the earth and of the surface which defines it, so as to let the earth become perfectly round, and that the production of winds occurs only in the bowels or holes of the earth; so that above the highest mountains neither clouds nor winds appear, and that there the air moves regularly in a circle as a universal body. Perhaps this is what Plato [73. The reference is to Pbaedo: 109b-c.] meant when he said that we inhabit the concavities and obscure parts of the earth, and that we have the same relation with respect to animals that live above the earth, as do in respect to us the fish that live in thicker humidity. This means that in a way the vaporous air is water, and that the pure air which contains the happier animals is above the earth, where, just as this Amphitrit [74.
Amphitrite was in Greek mythology the daughter of Nereus and the wife of Poseidon and, therefore, the goddess of the sea.] [ocean] is water for us, this air of ours is water for them. This is how one may
respond to the argument referred to by Nundinio; just as the sea is not on the surface, but in the bowels of the earth, and just as the liver, this source of fluids, is within us, that turbulent air is not outside, but is as if it were in the lungs of animals.
Smi. Now how is it that we see the entire [celestial]
hemisphere though we inhabit the bowels of the earth?
THE. Because of the mass of the sperical earth, it happens not only on the outermost points of the surface, but also on interior [lower] points, that from place to place a convexity is given to [permit] the sight of the [whole] horizon; in that case there does not arise that impediment which we see when between our eyes and a part of the sky a mountain interposes itself, which, by being close, can destroy the perfect vision of the circle of the horizon. The distance of those mountains which follow the convexity of the earth, which is not plain but spherical, causes them to be invisible from the bowels of the earth; as one may to some extent see this in the present figure [75. Another frustrating effort by Bruno to use geometry.]  where the true surface of the earth is ABC, within which surface are the many particulars of the sea and of other continents, such for instance M, from which point we see no less the entire hemisphere than from the point A and from other points of the outermost surface. The reason for this is twofold: the greatness of the earth and its convex circumference; therefore, the point M is not blocked so that [from there) one may not see the entire hemisphere,
because the very high mountains do not interpose with respect to M, as does the line MB, (which would, I believe, happen, were the earth's surface flat), but rather as with the line MC, MD does not suffer such impediment, as this is seen in virtue of the circumferential arc. And note
furthermore that as M relates to C and M to D, so does K to M. Therefore, one need not consider a fable what Plato said of very great concavities and laps of the earth. [76. The
conclusion should speak for itself.]
Smi. I would like to know if those who are near the highest mountains are inconvenienced by that impediment?
THE. No; but rather those who are near the smaller mountains, because the mountains are not very high unless they are so high as to cause their
magnitude to appear insensible to our vision [77. A reasoning as self-defeating as Bruno's subsequent rambling about mountains.] Sothat in such a way one may understand [the situation about] many other artificial horizons, in which the accidents of some cannot
produce alteration of some others; however, by 'very high mountains' we do not mean the Alps, and the Pyrenees, and the like, but like the entire France which is between two seas, the northern Ocean and the southern Mediterranean; from these seas one always ascends [in going] toward Auvergne, as also from the Alps and the Pyrenees, which once were the peaks of a gigantic mountain range broken into fragments as time went on [78.
One should be on guard against reading a very advanced geological theme into these statements. In the next breath Bruno is back into a theme more Hermet. ic than scientific, the perpetual cyclic process of everything.] while elsewhere other mountains formed through the vicissitude Of the renovation of parts of the earth), and now form so many particular mountains which we call peaks. Therefore, concerning the example offered by Nundinio about the Scottish mountaing, [79. One wonders if Nunclinio's dicta on Scottish mountains had more sense than had Bruno's subsequent declaration about that exceedingly high mountain in the middle of England.] where he once perhaps stayed, it is clear that he is unable to grasp what is meant by very high mountains. For, in truth, the whole island of Britannia is a mountain which raises its head above the waves of the Ocean sea; the top of that mountain must be at the more eminent point of the island; that top joins the tranquil part of the air, and thus proves that this should be one of those highest mountains, where is perhaps the region of the happier animals. Alexander of Aphrodisias
[80. Alexander of Aphrodisias (fl. 200 AD), a philosopher famed for his ardent defense of Aristotle. Two commentaries of his on Aristotle's work are extant, of which one is on the Meteorologica, but it does not contain the detail in question about Mount Olympus.] reasons so about Mount Olympus, where
the evidence of the ashes of sacrifices shows the condition of the highest mountain and of the air above the confines and parts of the earth.
Smi. You have satisfied me most sufficiently, and you have excellently opened many sccrets of nature which lay hidden under that key. Thus, you have replied to the argument taken from winds and clouds; there remains yet the reply to the other [argument] which Aristotle submitted in the
second book of On the Heavens,[81. See section 296b.] where he states that it would be impossible that a stone thrown high up could come down along the same perpendicular straight line, but that it would be necessary that the exceedingly fast motion of the earth should leave it far behind toward the west. Therefore, given this projection [back] into the earth, it is necessary that with its motion there should come a change in all relations of straightness and obliquity; just as there is a difference between the motion of the ship and the motion of those things that arc on the ship which if not true it would follow that when the ship moves across the sea one could never draw something along a straight line from one of its corners to the other, and that it would not be possible for one to make a jump and return with his feet to the point from where he took Off.[82. Hcre Smith provides some, of the answer to his own question.]
[THE]. With the earth move, therefore, all things that are on the carth. [83. Theophil's answer simply states something that was already a well-known notion, namely, that objects on the surface of the earth share in the earth's motion (rotation), if indeed such is the case.] If, therefore, from a point outside the earth something were thrown upon the earth, it would lose, because of the latter's motion, its straightness as would be scen [84. The figure wholly lacks the lettering referred to in the text. ] [Fig. 6]
on the ship AB moving along a river, if someone on point C of the riverbank were to throw a stone along a straight line, [and] would see the stone miss its course [target] by the amount of the velocity of the [ship's] motiom. [85. The case of a
stone thrown horizontally toward the ship was hardly a felicitous one, as the rotation of the earth presented an additional problem in the context of such motion.] But if someone were placed high on the mast of that ship, move as it may however fast, he would not miss his target at all, so that the stone or some other heavy thing thrown downward would not come along a straight line from the point E which is at the top of the mast, or cage, to the point D which is at the bottom of the mast, or at some point in the boweis and body of the ship. Thus, if from the point D to the point E someone who is inside the ship would throw a stone straight [up], it would return to the bottom along the same line however far the ship moved, provided it was not subject to any pitch and roll.
Smi. From the consideration of this difference there opens the door to so many and highly important secrets of nature and of profound philosophy; indeed, it is a frequent and little noticed case how great is the difference between he who cures himself and he who is cured by another: it is often noticed that we derive greater pleasure and
satisfaction from taking the food with our own hands than from the hand of someone else. As soon as children can use their own utensils to take food, they do not rely willingly on others; as if nature would in some way make them
understand that what provides for little pleasure, secures but small profit. See the children who are nursed, how they cling with their hands to the breast. And I am never so shocked by theft as when done by a domestic servant,
because, I do not know why, someone familiar brings along more of a shadowy portent than does a stranger, by
conjuring up the form of evil genius and of fearful omen.
[86. Rather obscure remarks.]
THF. Now to turn to the subject. If there are two, of which one is inside the ship that moves and the other outside it, of which both one and the other have their hands at the same point of the air, and if at the same place and time one and the other let a stone fall without giving it any push, the stone of the former would, without a moment's loss and without deviating from its path, go to the prefixed place, and that of the second would find itself carried backward.
This is due to nothing else except to the fact that the stone which leaves the hand of the one supported by the ship, and
consequently moves with its motion, has such an impressed virtue [impetus] [87. The notion of impressed virtue (impetus) was an all-important link in the development toward the formulation of inertial motion by Galileo, Descartes and Newton, and it had a long history antedating Bruno, as has been amply documented in the studies of P. Duhem, A. Meier and others. ], which is not had by the other who is outside the ship, because the stones have the same gravity, the same
intervening air, if they depart (if this is possible) from the same point, and arc given the same thrust.
From that difference we cannot draw any other explanation except that the things which are affixed to the ship, and belong to it in some such way, move with it: and one of the stones carries with itself the virtue [impetus] of the mover which moves with the ship. The other does not have the said participation. From this it can evidently be seen that the ability to go straight comes not from the point of motion where one starts, nor from the point where one ends, nor from the medium through which one moves, but from the efficiency of the originally impressed virtue [impetus], on which depends the whole difference. And it seems to me that enough consideration was given to the propositions of Nundinio.
Smi. So tomorrow we shall see each other again to hear the propositions which Torquato submits.
PRU. Fiat [So be it].
End of the Third Dialogue