Abstract
Isaac Newton’s scientific thought is all too often presented as if it had been dominated by a single philosophical slogan: Hypotheses non fingo! The scholars who have applied this expression to all Newton’s writings evidently take as axiomatic that Newton’s stand on hypotheses never changed from the early period of 1672, when Newton published his first paper on color, to 1712, when he wrote out the General Scholium for the second edition of the Principia, and in it imbedded those three famous words about hypotheses. But such a supposed constancy of Newton’s views will surely appear astonishing to anyone who is acquainted with the development of thought in so long a span (some 40 years) in the creative life of a reflecting scientist like Newton!
This essay was also published in Physis, Rivista Internazionale di Storia della Scienza 8 (1966) 163-184.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
The research on which this article is based has been generously supported by a grant from the National Science Foundation. I should like to acknowledge the contributions of Mrs. Anne Whitman, who has worked with me on the study of Newton’s Latin texts and on the preparation of English versions of the passages quoted below.
This edition is to be a joint publication of the Harvard University Press and Cambridge University Press.
The topics explored in this article have been more fully developed in the Wiles Lectures, delivered in May 1966 at the Queen’s University, Belfast, Northern Ireland: to be published under the general title of Transformations of Scientific Ideas: Variations on Newtonian Themes by Cambridge University Press. To some extent, this article is a summary of a portion of the second of these lectures.
Quoted from Florian Cajori’s revision of Andrew Motte’s translation (1729) of the Principia, Berkeley, Calif., 1934, p. 546. This translation is referred to below as ‘Motte-Cajori’. I have, here and elsewhere, made some changes in the Motte-Cajori version.
Ernst Mach, The Science of Mechanics, Chicago 1919, second English ed. based on fourth German ed. [1901], Ch. II, pt. 3, § 6, p. 193: “Newton’s reiterated and emphatic protestations that he is not concerned with hypotheses as to the causes of phenomena, but has simply to do with the investigation and transformed statement of actual facts, — a direction of thought that is distinctly and tersely uttered in his words ‘hypotheses non fingo’, ‘I do not frame hypotheses’, — stamps him as a philosopher of the highest rank.”
See Alexandre Koyré, Newtonian Studies, Cambridge and London, 1965: II: ‘Concept and Experience in Newton’s Scientific Thought’, and VI: ‘Newton’s ‘Regulae Philosophandi”.
Motte-Cajori, p. 419.
Ibid.
Hermann Weyl, Philosophy of Mathematics and Natural Science, Princeton, N.J., 1949, pp. 100–101.
See W. W. Rouse Ball, Essay on Newton’s “Principia”, London 1893, p. 110.
J. Edleston (ed.), Correspondence of Sir Isaac Newton and Professor Cotes, London 1850, p. 155: Letter LXXXI, Newton to Cotes, March 28, 1713.
This part of the subject is developed in full in the second of the Wiles Lectures.
It reads (Motte-Cajori, p. 400): “In experimental philosophy we are to look upon propositions inferred by general induction from phenomena as accurately or very nearly true, notwithstanding any contrary hypotheses that may be imagined, till such time as other phenomena occur, by which they may either be made more accurate, or liable to exceptions.” The comment is short, and reads: “This rule we must follow, that the argument of induction may not be evaded by hypotheses.”
These alterations are displayed in full in the Apparatus Criticus of the forthcoming edition of Newton’s Principia (see note 2 supra). The changes from the first to the second edition of the Principia are discussed in I. B. Cohen, Franklin and Newton, Cambridge 1956, pp. 131sqq., and in Alexandre Koyré, Newtonian Studies, Cambridge and London, 1965, ch. vi — Newton’s ‘Regulae Philosophandi’.
I shall not explore here the contents of ‘Hyp. V–IX’ which became ‘Phaen. I–VI’.
Phaen. II appears for the first time in the second edition. It states that the law of areas and Kepler’s harmonic law hold for the motion of Saturn’s satellites. In the first edition, Newton refers to the single satellite of Saturn discovered by Huygens, e.g., in Corol. I to Prop. V, but does not acknowledge the existence of further satellites discovered by Cassini.
The first edition (1687) has been reprinted in facsimile by Messrs. William Dawson & Sons, of London. Hyp. III occurs on p. 402.
Translated from the Latin text of the first edition, pp. 410-411. The alterations in this Corollary are discussed below. Corol. 2: “Igitur corpora universa quae circa Terrain sunt, gravia sunt in Terram; & pondera omnium, quae aequaliter a centro Terrae distant, sunt ut quantitates materiae in iisdem.”
Motte-Cajori, pp. 398-399, with Motte’s original ‘intension’ restored for Cajori’s ‘intensification’. The discussion of the Rule consists of two paragraphs, of which I have quoted only a portion of the first. Newton gives other examples of the way in which we may extend knowledge based upon experience of objects within the reach of our experiments to those which are not, including hardness, impenetrability, mobility, and inertia. In a second paragraph, Newton argues for the universality of gravitation. The final four sentences appear in print for the first time in the third edition of the Principia, but are present in Newton’s annotated and interleaved copies of the second edition, in his personal library: “Attamen gravitatem corporibus essentialem esse minime affirmo. Per vim insitam intelligo solam vim inertiae. Haec immutabilis est. Gravitas recedendo a terra, diminuitur.” These have been translated into English (Motte-Cajori, p. 400): “Not that I affirm gravity to be essential to bodies: by their vis insita I mean nothing but their inertia. This is immutable. Their gravity is diminished as they recede from the earth.” Motte (1729) wrote, “By their vis insita I mean nothing but their vis inertiae”, but Cajori modernized both the English style and the sense by altering ‘force of inertia’ to ‘inertia’.
Ibid., pp. 413-414.
Cf. W. P. D. Wightman: [1] ‘Gregory’s Notae in Isaaci Newtoni Principia Philoso-phiae’, Nature 172 (1953), 690; [2] ‘Aberdeen University and the Royal Society’, Notes and Records of the Royal Society 11 (1955), 148sqq.; [3] ‘David Gregory’s Commentary on Newton’s “Principia’”, Nature 179(1957), 393-394.
Transcribed and translated from the MS.
I omit here any discussion of Newton’s ‘ether’, a’ spirit’ diffused everywhere, in relation to the Aristotelian ‘quinta essentia’ or ‘fifth element’, of which the heavenly bodies are composed.
Opticks, reprint of fourth ed., New York 1952, Qu. 31, p. 400.
These two copies are, respectively, in the Trinity College Library and the University Library, Cambridge. There are two similar copies of the second edition, one annotated and the other interleaved and annotated. All the MS corrections, emendations, and additions entered by Newton into these four copies are included among the variae lectiones in the Apparatus Criticus of the forthcoming edition of the Principia (along with the differences among the three printed editions and the MS from which the first edition was printed).
This copy is in the Trinity College Library.
All of these versions are given in full in the second of the Wiles Lectures.
I have, of course, translated the Latin text into English.
Since that statement begins “Nam proprietates corporum…” we may assume that the alteration, by which ‘proprietates’ had been inserted into the statement of Hypothesis III, had already been made.
See Christiaan Huygens, Oeuvres, vol. X (1905), pp. 147–155.
The statement of Regula III in the interleaved copy (see note 25 supra) is followed by the two paragraphs of discussion, omitting (as does the second edition) the final four sentences printed in the third edition, mentioned in note 19 supra. It is of interest to note that in the interleaved copy (in the University Library, Cambridge University), the expression “viribus quibusdam (quas vires inertiae vocamus)” is simply “viribus quibusdam”, and “vis inertiae” and “vires inertiae” are “impetus” (singular). Here, the title ‘Reg. III’ replaces an original ‘Hypoth. III’.
In the final form of explanation of Rule III, as published in the Principia, Newton says: “For since the qualities of bodies are only known to us by experiments, we are to hold for universal all such as universally agree with experiments; and such as are not liable to diminution can never be quite taken away.”
Maurice Mandelbaum, Philosophy, Science, and Sense Perception: Historical and Critical Studies, Baltimore 1964, ch. 2 — ‘Newton and Boyle and the Problem of Transdiction’, pp. 61 sqq.
This topic is explored in the third of the Wiles Lectures.
Later on, Newton contemplated yet another ‘Hypoth. IV, and added it on this same page, evidently deciding to throw out the old ‘Hypoth. III’ (now become ‘Hypoth. IV’). This additional ‘Hypoth. IV’ reads (in translation): “Things which agree as to all their known qualities with other kinds of things are not to be considered as new kinds of things.” The Latin original reads: “Pro novis rerum generibus habenda non sunt quae cum aliis rerum generibus quoad omnes suas notas qualitates congruunt.” The relation between this hypothesis and the new ‘Hypoth. III’, about qualities which cannot be intended or remitted, is not clear, nor is it obvious as to the purpose this additional hypothesis may have been intended to serve.
Translated from the Latin: “Peripateticorum et Cartesianorum est Hypothesis & contra eorum praejudicia solummodo dirigitur.”
Translated from the Latin: “[Sic statuunt del.] Peripateticorum [changed from Peripatetici] [Epicureorum changed from Epicurei del.] & Cartesianorum [changed from Cartesiani] est Hypothesis et [non absolute statuitur sed del.] contra eorum praejudicia solummodo dirigitur. [a quibus statuitur. Siquis aliter sentiat contra hunc non del.].”
I have given an English translation of this Corol. 2 on pp. 309-310 above.
Translated from the Latin: “Patet in sensibilibus omnibus per experientiam ideoque de insensibilibus etiam intelligendum est per Hypoth. III.”
The exact nature of Newton’s argument “against those who admit” either of these small hypotheses would take us too far afield, although it is extremely interesting; this subject is explored fully in the Wiles Lectures.
This is found on page 129v. of (U.L.C.) MS Add. 3965.
The date is fixed by the appearance of Hypoth. III in final form in a dated MS of Fatio de Duillier’s. See note 30 above.
“The ffourth book concerning the nature of Light &ye power of bodies to refract & reflect it.”
I am quoting from some MSS in English (U.L.C. MS Add. 3970).
Newton has crossed out an earlier version of these words, reading: “Philosophiae naturalis Principia mathematica by such a mathematical way of arguing as has procured the assent of [given satisfaction crossed out] all the ablest Mathematicians…”.
Newton has crossed out “but now those things being received by Mathematicians”.
See A. Koyré, ‘Les ‘Queries’ de l’Optique’, Archives Internationales d’Histoire des Sciences 13 (1960), 15–29.
I. B. Cohen and R. E. Schofield (ed.), Isaac Newton’s Papers & Letters on Natural Philosophy, Cambridge 1958, pp. 85, 92, from an English translation of the Latin in Phil. Trans. No. 84. 17 June 1672, p. 4093. This letter is printed from the MS in full in vol. I of Newton’s Correspondence, Cambridge 1959, pp. 142, 144.
This was not printed in Newton’s lifetime, but was published by Thomas Birch in his History of the Royal Society, London 1757, vol. 3, almost continuously in pp. 247–305; it is reprinted in Newton’s Papers & Letters (see note 48 above), pp. 177-235.
Newton’s Papers & Letters, pp. 99, 106; Phil. Trans. 85, 15 July 1672, p. 5014 (misprinted as 4014); Correspondence, vol. I, pp. 164, 169.
This is so different a statement from Newton’s first letter to Pardies that one must read it with caution. Newton had previously said that his aim had been not to produce an hypothesis, but a theory. The theory consisted of establishing certain properties of light from experiment, not properties which were vain and empty speculations, or hypotheses. Now he says that the best method of proceeding is to establish properties by experiment, and then, and only then, to proceed more slowly to hypotheses to explain them.
Let me add a note on Newton’s explanation of what he meant by light: “By light therefore I understand, any being or power of a being, whether a substance or any power, action, or quality of it, which proceeding directly from a lucid body, is apt to excite vision.” This is pure instrumentalism: Newton says that light merely is any thing or process which starts from a lucid body and excites vision. As to ‘rays of light’ he understands light’s “least or indefinitely small parts, which are independent of each other; such as are all those rays which lucid bodies emit in right lines, either successively or all together”.
I have not attempted to display here the several varieties of ‘hypotheses’ which occur in the different writings of Newton’s. This topic is explored in ‘Newton’s Use of the Word Hypothesis’, Appendix One to I. B. Cohen, Franklin and Newton, Cambridge 1956, and in the second of the Wiles Lectures.
Of course, we have seen that three statements in the later editions of the Principia are marked ‘Hypothesis’, one in Book Two and two in Book Three, but they are not in the conspicuous position that ‘Hypotheses’ occupied at the beginning of Book Three in the first edition. And in the Opticks, Newton presented his hypotheses innocently in the form (or guise) of rhetorical Queries.
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1969 D. Reidel Publishing Company, Dordrecht, Holland
About this chapter
Cite this chapter
Cohen, I.B. (1969). Hypotheses in Newton’s Philosophy. In: Cohen, R.S., Wartofsky, M.W. (eds) Boston Studies in the Philosophy of Science. Boston Studies in the Philosophy of Science, vol 5. Springer, Dordrecht. https://doi.org/10.1007/978-94-010-3381-7_8
Download citation
DOI: https://doi.org/10.1007/978-94-010-3381-7_8
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-010-3383-1
Online ISBN: 978-94-010-3381-7
eBook Packages: Springer Book Archive