[26 ] The catalogue attributed to Hipparchus was based by him on the earlier one of Aristillus and Timocharis, thus making possible his discovery of the precession of the equinoxes. [For Hipparchus’ achievements see Heath, Manual, 395–9.]
[27 ] Too sweeping a condemnation; the attitudes of Stoics and Epicureans towards
‘Nature’ differed from that of the ‘astronomers’ but were far from negligible.
[28 ] [Cf. LRBL ii.213–14 (ed. Lothian, 175–6), referring to the time of Cicero: ‘Rhetoric and Logic or Dialectic were these undoubtedly which had made the greatest progress amongst the ancients, and indeed, if we except a little of Morals, were the only ones which had been tolerably cultivated. These, therefore, were the fashionable sciences . .
.’]
[29 ] [ Letters to Atticus, II.6.1.]
[30 ] [Like Copernicus (see § 28 and note 51 below), Smith assumes the genuineness of the Placita Philosophorum preserved among the writings of Plutarch. On its real origin, see J. Burnet, Early Greek Philosophy, ed. 3 (1920), 34.]
[31 ] [ Natural History, II, especially 54, 95.]
[32 ] While Cicero would probably have been incapable of following the mathematical arguments, his remarks relating to what we might call ‘philosophy of science’ (e.g. in De Natura Deorum, De Divinatione) have a distinctively modern ring.
[33 ] [Mechanistic analogies were common in the eighteenth century and Smith used them widely. He writes of the universe as like a machine in Ancient Physics, 9, and in TMS I.i.4.2, VII.ii.1.37; and of society similarly in TMS VII.iii.1.2, VII.iii.3.16.]
[34 ] [Cf. Languages, 41: ‘All machines are generally, when first invented, extremely complex in their principles, and there is often a particular principle of motion for every particular movement which it is intended they should perform. Succeeding improvers observe, that one principle may be so applied as to produce several of those
movements; and thus the machine becomes gradually more and more simple, and
produces its effects with fewer wheels and fewer principles of motion.’ Smith compares with this the development of languages from original complexity to later simplicity but considers that, while the process of simplification makes machines ‘more and more perfect’, it makes languages ‘more and more imperfect’. The whole passage recurs in summary form in LRBL i.34. (ed. Lothian, 11).]
[35 ] [Proclus (A.D. 410–85), the Neoplatonist philosopher. His extant works include
‘the Hypotyposis of Astronomical Hypotheses, a sort of easy and readable introduction to the astronomical system of Hipparchus and Ptolemy’ (Heath, Manual, 517).
Theon of Alexandria (4th century A.D.) wrote a commentary on Ptolemy’s Syntaxis.
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Heath, ibid., 516, explains its value.]
[36 ] [Cf. III.1 above.]
[37 ] Smith gives a somewhat optimistic view of Muslim ‘toleration’.
[38 ] [At the period in question, many Greek scientific works, especially those of Galen and Hippocrates, were translated into Syriac as well as into Arabic: see M. Meyerhof, in Sir T. Arnold and A. Guillaume (eds.), The Legacy of Islam (1931), 316 ff.; E. Gilson, La Philosophie au moyen âge (1944), and R. Walzer, ‘On the Arabic versions . . . of Aristotle’s Metaphysics’, Harvard Studies in Classical Philology, lxiii (1958), 218–21.]
[39 ] The term ‘nation’ is inappropriate: many of the greatest were Persians.
[40 ] i.e. al–Ma’mūn (786–833), 7th Abbasid Caliph from 813 until his death. [On the Tables of al–Ma’mūn, see Baron Carra de Vaux in The Legacy of Islam, 380–1, chapter on ‘Astronomy and Mathematics’.]
[41 ] [The Biblical Shinar. Other accounts say that the measurements were made by two companies of astronomers.]
[42 ] [On these developments see C. H. Haskins, Studies in the History of Medieval Science (1927), especially chap. 1 on translators from the Arabic in Spain, and chap. 5
on twelfth–century writers on astronomy. For the versions of Ptolemy see 103 ff.]
[43 ] [See Gilson, op. cit., 344–67, 377–90.]
[44 ] Here and elsewhere Smith fails to stress that it was Ptolemy’s system (embodying the equant and based on the unsurpassed observations of Hipparchus) that was adopted in ‘learned’ circles. But see § 26 below.
[45 ] Georg von Peuerbach or Peurbach (1423–61) was of course a humanist, not a
‘schoolman’.
[46 ] [See § 22 and note 40 above.]
[47 ] [Alfonso X (b. 1221), ‘the Wise’, King of Castile and León, 1252–84. See Haskins, op. cit., 16–17, and literature there cited. The legend of his ‘whimsical impiety’ is of late authority.]
[48 ] Additional spheres (ninth and tenth) were introduced to account for two (actually imaginary) anomalies in the rotation of the ‘eighth sphere’ (of the fixed stars). One of these anomalies was ‘trepidation’, mentioned by Milton, Paradise Lost, iii.483.
[49 ] [Johannes Müller (1436–76) assumed the name of Regiomontanus as the
Latinized form of his birthplace, Königsberg (bei Hassfurt, W.Germany). For his life and achievements, see the article in the Dictionary of Scientific Biography, vol. xi (1975), http://oll.libertyfund.org/Texts/LFBooks/Smith0232/GlasgowEdition/PhilosophicalSubjects...
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348–52.]
[50 ] [Preface to De Revolutionibus Orbium Coelestium. ]
[51 ] [See Heath, Aristarchus of Samos, 301. The relevant passages are in Copernicus’
De Revolutionibus, I.5, and in the Preface. Copernicus assumed that in the Placita Philosophorum he had before him a genuine work of Plutarch (see note 30 above).
He was apparently well aware that in the third century B.C. Aristarchus of Samos had suggested the heliocentric hypothesis, a fact which is unambiguously stated by
Archimedes in The Sand–Reckoner; but he suppressed a note in which he made reference to this. Thus, in his published work, there remains only the mention of Pythagoreans who had anticipated him—to the extent that they assigned a planetary movement, as well as axial rotation, to the earth.
Smith has nowhere mentioned the remarkable achievement of Aristarchus. Either it
escaped him, or he has deliberately confined himself in this essay to those ancient systems which enjoyed wide influence.]
[52 ] A perceptive comment in respect of the Sun and ‘central fire’—a distinction not always recognized by later historians. But the term ‘ecliptic’ is here misleading (see the editor’s Introduction, 16).
[53 ] Smith’s expression ‘without the embarrassment of epicycles’, repeated more than once, must be taken to refer only to the shapes and directions of the apparent motions.
In order to avoid the use of Ptolemy’s equant, Copernicus in fact employed more
epicycles than Ptolemy had done. Smith partially corrects this in § 53 below.
[54 ] ‘Simple’ only to a first approximation.
[55 ] It was of course for the more accurate calculations of the positions of the planets that the greater part of astronomy up to and including the Renaissance had been
undertaken.
[56 ] [This appears to be a distorted report at second hand or possibly a confusion between Tycho Brahe and someone else. The supposed quotation is uncharacteristic of Tycho, who is usually respectful to Copernicus, even though he was ready to describe both the Copernican and the Ptolemaic systems as ‘absurd’.]
Smith’s spelling of the name, here and elsewhere, though representing more nearly the Danish pronunciation, is corrected in the Dublin edition of the same year.
[57 ] In fact the Commentariolus (not the De Revolutionibus), privately circulated in 1514. Only three near–contemporary MSS. of the Commentariolus are known, one recently discovered in the University of Aberdeen. It is not to be confused with the Narratio Prima written by his disciple Rheticus.
[58 ] [A striking exception to Smith’s generalization, in TMS III.2.20, that
mathematicians and natural philosophers, ‘who may have the most perfect assurance, both of the truth and of the importance of their discoveries, are frequently very http://oll.libertyfund.org/Texts/LFBooks/Smith0232/GlasgowEdition/PhilosophicalSubjects...
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indifferent about the reception they may meet with from the public’.]
[59 ] Rheticus circulated his Narratio Prima in 1540 to test the likely reception of a full account that he was trying to persuade Copernicus to publish. The Lutheran pastor, Andreas Osiander, who saw Copernicus’ great work through the press, categorically stated (anonymously, as if by Copernicus himself) that the system was not to be taken as ‘physically’ true. Erasmus Reinhold, as Smith states, used the system as a basis for calculating the Prutenic tables, but it now appears doubtful whether he accepted the system except as a basis for this calculation.
[60 ] i.e. the De Revolutionibus Orbium Coelestium (1543).
[61 ] [Erasmus Reinhold (1511–53), author of Prutenicae Tabulae Coelestium Motum (1551), which were adopted as the basis for the Gregorian reform of the Julian calendar in 1583.]
[62 ] This is a very interesting and perceptive assessment. The alleged acceptance by
‘astronomers only’ is indeed a serious historical mis–statement: Thomas Digges, Robert Recorde, Reinerus Gemma, and especially Giordano Bruno, were none of them
‘astronomers’ except in a loose sense; no ‘professional’ except Rheticus accepted it until the seventeenth century. Nevertheless, this rather gives force to Smith’s philosophical approach.
[63 ] As Copernicus, De Revolutionibus, I.8 (following Virgil, Aeneid, iii.72), had noticed.
[64 ] [Cf. External Senses, 12: ‘Great masses, perhaps, are, according to the ordinary habits of the imagination, supposed to be more fitted for rest than for motion.’ Smith then goes on to say that the teaching of modern science makes it ‘scarcely possible to refuse our [rational] assent’ to the motion of the earth ‘with a rapidity that almost passes all human comprehension’.]
[65 ] It is largely true that the ‘schools’ (i.e. the universities) confined themselves to the Peripatetic (i.e. the Aristotelian) philosophy; but the powerful strain of Neoplatonism (largely mediated through the Hermetic philosophy) should not be overlooked. The
consequential ‘wind’ had been considered by Ptolemy; see § 40 below.
[66 ] [ De Revolutionibus, I.9.]
[67 ] [ Discourses on Two New Sciences, IV; in Opere (National Edition, Florence, 1890–
1910), viii. 268 ff.]
[68 ] Tycho Brahe is to be regarded less as the ‘restorer’ of astronomy than, at least as an observer, the first of the ‘moderns’. Also, in the pursuit of his passion he ‘wasted’ not only his own ‘fortunes’ but those of his defenceless tenants.
[69 ] Tycho’s hypothesis was not altogether ‘new’. See the editor’s Introduction, 18–
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19.
[70 ] The absolute priority of Galileo in turning the newly invented telescope on the heavens is now questioned. The Englishman, Thomas Harriot (1560–1621), was
observing the Moon independently about the same time.
[71 ] [Galileo’s discovery of the phases of Venus was first announced in his letter of 1
January 1610/11 to Giuliano de’ Medici, Ambassador of the Duke of Tuscany at the
Court of the Emperor Rudolph II in Prague. It is published in Galileo’s Opere (National Edition), xi.11–12. His description of the mountains and seas on the Moon had,
however, already been published in his Sidereus Nuncius, 1610 ( Opere, iii.59 ff.).
Smith’s reference to these discoveries in nonchronological order might imply that he followed the description in Colin Maclaurin’s Account of Sir Isaac Newton’s Discoveries, 54. See § 58 and note 94 below.]
[72 ] [Michael Maestlin (1550–1631), Professor of Mathematics at Tübingen, where he taught and became friendly with Kepler.]
[73 ] Smith omits to mention the most intractable objection to the Copernican system, the absence of any observed stellar parallax, i.e. the inference that if the Earth moves round the Sun, every star should be seen to make a roughly circular revolution once a year in the opposite sense. The absence of any such observed motion implied a then inconceivable distance of the stars from the Earth. Such stellar parallax was not measured until 1838.
[74 ] [Cf. II.4 above.]
[75 ] Kepler was indeed usually ‘indigent’, since his employers were commonly
reluctant or unable to pay up; but when invited by Tycho to join him as an assistant, Kepler was already far from ‘obscure’.
[76 ] Smith’s account of Kepler’s work, though highly condensed and chronologically
‘rearranged’, is substantially correct.
[77 ] [Cf. LJ(A) vi.14: ‘the constantly varying direction of the circle, which at the same time is allways similar and easily conceived, is preferred to the more varied figures of the elipse, parabola, and hyperbola, and the Archimedean spirrall, . . . as it is more easily conceved than these, whose nature can not at first sight be understood.’]
[78 ] There is a good deal of special pleading, if not of actual inconsistency, in the argument as set out here.
[79 ] For ‘equality’ read ‘uniformity’.
[80 ] For a recent reassessment of the response to Kepler’s ‘new astronomy’ see J.
Russell, S. J., ‘Kepler’s Laws of Planetary Motion, 1609–1666’, British Journal of the History of Science, ii (1964), 1–24.
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[81 ] [Pierre Gassendi (1592–1655), best known as a philosopher, but also, as Smith implies, a scientist of some repute.]
[82 ] [In Le Monde, completed in 1633 but not published (presumably because of its acceptance of the Copernican system of astronomy which Galileo had just been forced to recant) until 1664, long after the death of its author. The basic doctrines of the work were nevertheless embodied in Principia Philosophiae (1664).]
[83 ] Seth Ward (1617–89) Savilian Professor of Astronomy at Oxford, Founder Fellow of the Royal Society, and Bishop of Exeter.
[84 ] Ismael Boulliau (various spellings, also known as Bullialdus—1605–94), author of Astronomia Philolaica (1645), was the first to apply the inverse square to planetary motion. [Ward criticized it in a work entitled In Ismaelis Bullialdi Astronomiae Philolaicae Fundamenta Inquisitio Brevis (1653) and Boulliau replied in Astronomiae Philolaicae Fundamenta clarius explicata . . . Adversa . . . Sethi Wardi impugnationem (1657).]
[85 ] [The text of the original edition has ‘vortices’, presumably a printer’s error.]
[86 ] [The text of the original edition has ‘many’, again simply a printer’s error.]
[87 ] [ Astronomia Nova (1609).]
[88 ] i.e. proportion.
[89 ] [ De Harmonice Mundi (1619).]
[90 ] ‘Cubes of their distances’ should be ‘cubes of their mean distances’.
[91 ] Giovanni Domenico Cassini (1625–1712), the first of a family of distinguished astronomers and virtual Director of the Observatory set up by the Académie Royale des Sciences, of which he was an early pensionnaire.
[92 ] [ Éléments de la philosophie de Newton (1738).]
[93 ] Cardinal Melchior de Polignac (1661–1742).
[94 ] [Colin Maclaurin (1698–1746), educated at the University of Glasgow, appointed Professor of Mathematics at Marischal College and the University of Aberdeen in 1717, and then at the University of Edinburgh in 1725 with the recommendation of Newton.
His Account of Sir Isaac Newton’s Discoveries was published posthumously in 1748.]
[95 ] [Newton’s discussion, at the beginning of Book III of the Principia, contains no definite statement to this effect, but Smith’s cautious form of expression does not imply otherwise.]
[96 ] [ Mysterium Cosmographicum (1596), chap. 20; Astronomia Nova (1609), chaps.
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33–4.]
[97 ] [See note 82 above.]
[98 ] Principles of Philosophy, II.36. When combined with Descartes’s further statement of the law of inertia (§63 below—‘Newton’s’ First Law of Motion, only partially envisaged by Galileo), this corresponds to the principle of the conservation of linear momentum (Newton’s Third Law). Recognizing that this does not apply to certain cases of impact, Leibniz claimed that it is not momentum (product of mass and velocity) but vis viva (product of mass and square of velocity) that is conserved. This cause célèbre among the savants of the eighteenth century was resolved partly by d’Alembert (see the
editor’s Introduction, 22) in Smith’s lifetime, and finally by Hermann von Helmholtz in 1847.
[99 ] [Smith has said nothing here about the earlier history of this explanation of motion in a plenum. Descartes took it from ancient Greek philosophers who, having denied the existence of void, had to deal with the same problem. The process described is used in Plato’s Timaeus, 79 A–E, to explain the mechanism of breathing. It is there termed periosis. Lucretius, i.370–83, illustrates it by the swimming of a fish, but only in order to oppose it and to insist upon the necessity for a void. The explanation was maintained by Hobbes in his De Corpore, chap. 22.12, chap. 25.3, as well as by Descartes. See A. E. Taylor, Commentary on Plato’s Timaeus (1928), 558.]
[1 ] But see the editor’s Introduction, 16.
[2 ] [§ 55 above.]
[3 ] A perceptive recognition of the approximative character of all ‘laws’ of nature. This implies the removal of the distinction between ‘natural’ and ‘celestial’ realms and the necessity for the later theory of perturbations, involving a good deal of heart–searching among theologians regarding the ‘perfection’ of the Creator.
[4 ] [Cf. Letter to the Authors of the Edinburgh Review, 5, where Smith again writes of Descartes’s natural philosophy as ‘almost universally exploded’ and of the advantages that it initially appeared to have. He also refers in TMS VII.ii.4.14 to the high regard in which Descartes’s theory of vortices was long held. In the Discours préliminaire to the Encyclopédie (1751), d’Alembert writes: ‘Si on juge sans partialité ces tourbillons devenus aujourd’hui presque ridicules, on conviendra, j’ose le dire, qu’on ne pouvoit alors imaginer mieux.’]
[5 ] Galileo ignored it in his famous polemical work, On the Two Chief Systems of the World, Ptolemaic and Copernican: its consistency with the observed phases of Venus would have weakened his insistence on the movement of the Earth.
[6 ] [Smith did not in fact say this before, but did say, in § 55 (cf. the next sentence here in § 66), that Descartes seems to have paid no attention to Kepler’s work on observations made by Tycho Brahe.]
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[7 ] This presumably marks the beginning of the material on Newton mentioned by
Smith’s editors in the concluding note to this section.
[8 ] An optimistic assessment. See the editor’s Introduction, 21–2.
[9 ] i.e. arc; a common spelling at that time.
[10 ] [ Principia, Book III, prop. 4, theorem 4.]
[11 ] [Ibid., prop. 19, problem 3.]
[12 ] See the editor’s Introduction, 7. [Smith had in his personal library a copy of the English translation of the book describing the results of the Lapland expedition: P.–L. M.
de Maupertuis, The Figure of the Earth, determined from observations made by order of the French King at the polar circle (1738). See H. Mizuta, Adam Smith’s Library (1967), 40. The results of the Peruvian expedition were given in Pierre Bouguer, La Figure de la terre (1749).]
[13 ] [For Hipparchus’ discovery of the precession, and his estimate of its period, see Heath, Aristarchus of Samos, 172–3.]
[14 ] [The text of the original edition has ‘procession’, no doubt a printer’s error.]
[15 ] [ Meterologica, I.6–7; 342b–345a.]
[16 ] [Smith may be alluding here to the observations of Johann Hevelius published in Prodromus Cometicus (1665), those of John Flamsteed in Historia Coelestis Britannica (1725), and those of Edmund Halley in Astronomiae Cometicae Synopsis (1705).]
[* ] It must be observed, that the whole of this Essay was written previous to the date here mentioned; and that the return of the comet happened agreeably to the prediction.
[17 ] The omission of the name of Edmund Halley (1656–1742) is unaccountable. For a discussion of the original footnote see the editor’s Introduction, 7–8.
[18 ] But see the editor’s Introduction, 21–2.
[19 ] [Cf. II.12 above.]
THE PRINCIPLES WHICH LEAD AND DIRECT PHILOSOPHICAL ENQUIRIES;
ILLUSTRATED BY THE HISTORY OF THE ANCIENT PHYSICS
From arranging and methodizing the System of the Heavens, Philosophy descended to the 1
consideration of the inferior parts of Nature, of the Earth, and of the bodies which immediately 1
surround it. If the objects, which were here presented to its view, were inferior in greatness or http://oll.libertyfund.org/Texts/LFBooks/Smith0232/GlasgowEdition/PhilosophicalSubjects...
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beauty, and therefore less apt to attract the attention of the mind, they were more apt, when they came to be attended to, to embarrass and perplex it, by the variety of their species, and by the intricacy and seeming irregularity of the laws or orders of their succession. The species of objects in the Heavens are few in number; the Sun, the Moon, the Planets, and the Fixed Stars, are all which those philosophers could distinguish. All the changes too, which are ever observed in these bodies, evidently arise from some difference in the velocity and direction of their several motions; but the variety of meteors in the air, of clouds, rainbows, thunder, lightning, winds, 2
rain, hail, snow, is vastly greater; and the order of their succession seems to be still more irregular and unconstant. The species of fossils, minerals, plants, animals, which are found in the Waters, and near the surface of the Earth, are still more intricately diversified; and if we regard the different manners of their production, their mutual influence in altering, destroying, supporting one another, the orders of their succession seem to admit of an almost infinite variety.
If the imagination, therefore, when it considered the appearances in the Heavens, was often perplexed, and driven out of its natural career, it would be much more exposed to the same embarrassment, when it directed its attention to the objects which the Earth presented to it, and when it endeavoured to trace their progress and successive revolutions.
To introduce order and coherence into the mind’s conception of this seeming chaos of dissimilar 2
and disjointed appearances, it was necessary to deduce all their qualities, operations, and laws of succession, from those of some particular things, with which it was perfectly acquainted and familiar, and along which its imagination could glide smoothly and easily, and without 3
interruption. But as we would in vain attempt to deduce the heat of a stove from that of an open chimney, unless we could show that the same fire which was exposed in the one, lay concealed in the other; so it was impossible to deduce the qualities and laws of succession, observed in the more uncommon appearances of Nature, from those of such as were more familiar, if those customary objects were not supposed, however disguised in their appearance, to enter into the composition of those rarer and more singular phaenomena. To render, therefore, this lower part of the great theatre of nature a coherent spectacle to the imagination, it became necessary to suppose, first, That all the strange objects of which it consisted were made up out of a few, with which the mind was extremely familiar: and secondly, That all their qualities, operations, and rules of succession, were no more than different diversifications of those to which it had long been accustomed, in these primary and elementary objects.
Of all the bodies of which these inferior parts of the universe seem to be composed, those with 3
which we are most familiar, are the Earth, which we tread upon; the Water, which we every day use; the Air, which we constantly breath; and the Fire, whose benign influence is not only required for preparing the common necessaries of life, but for the continual support of that vital principle which actuates both plants and animals. These, therefore, were by Empedocles, and the other philosophers of the Italian school, supposed to be the elements, out of which, at least, all the inferior parts of nature were composed. The familiarity of those bodies to the mind, naturally disposed it to look for some resemblance to them in whatever else was presented to its consideration. The discovery of some such resemblance united the new object to an assortment of things, with which the imagination was perfectly acquainted. And if any analogy could be observed betwixt the operations and laws of succession of the compound, and those of the simple objects, the movement of the fancy, in tracing their progress, became quite smooth, and natural, and easy. This natural anticipation, too, was still more confirmed by such a slight and inaccurate analysis of things, as could be expected in the infancy of science, when the curiosity of mankind, http://oll.libertyfund.org/Texts/LFBooks/Smith0232/GlasgowEdition/PhilosophicalSubjects...
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