Isaac Newton

Isaac Newton


Sir Isaac Newton was an English physicist, mathematician, astronomer, alchemist, inventor and natural philosopher. He is often regarded as the most influential scientist in history and is best known for discovering the Laws of Gravity.


  • Amicus Plato — amicus Aristoteles — magis amica veritas
    • Plato is my friend — Aristotle is my friend — but my greatest friend is truth.
    • These are notes in Latin that Newton wrote to himself that he titled: Quaestiones Quaedam Philosophicae [Certain Philosophical Questions] (c. 1664)
    • Variant translations: Plato is my friend, Aristotle is my friend, but my best friend is truth.
      Plato is my friend — Aristotle is my friend — truth is a greater friend.

  • If I have seen further it is only by standing on the shoulders of giants.
    • Modernized variants: If I have seen further it is by standing on the shoulders of giants.
      If I have seen farther it is by standing on the shoulders of giants.
    • Letter to Robert Hooke (15 February 1676) [dated as 5 February 1675 using the Julian calendar with March 25th rather than January 1st as New Years Day, equivalent to 15 February 1676 by Gregorian reckonings]
    • variant of mathematician Peter Winkler: "If I have seen further it is by standing on the shoulders of Hungarians."
    • Origin: Pigmaei gigantum humeris impositi plusquam ipsi gigantes vident.

  • I have not been able to discover the cause of those properties of gravity from phenomena, and I frame no hypotheses; for whatever is not deduced from the phenomena is to be called a hypothesis, and hypotheses, whether metaphysical or physical, whether of occult qualities or mechanical, have no place in experimental philosophy.
    • Letter to Robert Hooke (15 February 1676) [5 February 1675 (O.S.)]

  • The 2300 years do not end before the year 2132 nor after 2370.
    The time times & half time do not end before 2060. .... It may end later, but I see no reason for its ending sooner. This I mention not to assert when the time of the end shall be, but to put a stop to the rash conjectures of fancifull men who are frequently predicting the time of the end, & by doing so bring the sacred prophesies into discredit as often as their predictions fail. Christ comes as a thief in the night, & it is not for us to know the times & seasons wch God hath put into his own breast.
    • An Historical Account of Two Notable Corruptions of Scripture (1704), regarding his calculations "Of the End of the World" based upon the prophecies of Daniel, quoted in Look at the Moon! the Revelation Chronology‎ (2007) by John A. Abrams, p. 141
    • Modern typographical and spelling variant:
    • This I mention not to assert when the time of the end shall be, but to put a stop to the rash conjectures of fanciful men who are frequently predicting the time of the end, and by doing so bring the sacred prophesies into discredit as often as their predictions fail.

  • To explain all nature is too difficult a task for any one man or even for any one age. 'Tis much better to do a little with certainty, & leave the rest for others that come after you, than to explain all things by conjecture without making sure of any thing.
    • Statement from unpublished notes for the Preface to Opticks (1704) quoted in Never at Rest: A Biography of Isaac Newton (1983) by Richard S. Westfall, p. 643

  • The folly of Interpreters has been, to foretell times and things by this Prophecy, as if God designed to make them Prophets. By this rashness they have not only exposed themselves, but brought the Prophecy also into contempt.
    The design of God was much otherwise.
    He gave this and the Prophecies of the Old Testament, not to gratify mens curiosities by enabling them to foreknow things, but that after they were fulfilled they might be interpreted by the event, and his own Providence, not the Interpreters, be then manifested thereby to the world.
    • Observations Upon The Apocalypse Of St. John (published posthumously 1733)

  • I have studied these things — you have not.
    • Reported as Newton's response, whenever Edmond Halley would say anything disrespectful of religion, by Sir David Brewster in The Life of Sir Isaac Newton (1831). This has often been quoted in recent years as having been a statement specifically defending Astrology. Newton wrote extensively on the importance of Prophecy, and studied Alchemy, but there is little evidence that he took favourable notice of Astrology. Brewster attributes the anecdote to the astronomer Nevil Maskelyne who passed it on to Oxford professor Stephen Peter Rigaud.

  • I do not know what I may appear to the world, but to myself I seem to have been only like a boy playing on the sea-shore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.
    • Memoirs of the Life, Writings, and Discoveries of Sir Isaac Newton (1855) by Sir David Brewster (Volume II. Ch. 27). Compare: "As children gath'ring pebbles on the shore", John Milton, Paradise Regained, Book iv. Line 330.
      • Recently the statement "I know not how I may seem to others, but to myself I am but a small child wandering upon the vast shores of knowledge, every now and then finding a small bright pebble to content myself with." has been attributed to Plato, but the earliest published occurrence of this seems to be in The Mindful Coach: Seven Roles for Helping People Grow (2004) by Douglas K. Silsbee, p. 13, where it is attributed to Plato without a sourced citation.

Sir Isaac Newton had on his table a pile of papers upon which were written calculations that had taken him twenty years to make. One evening, he left the room for a few minutes, and when he came back he found that his little dog "Diamond" had overturned a candle and set fire to the precious papers, of which nothing was left but a heap of ashes.

  • By always thinking unto them. ... I keep the subject constantly before me and wait till the first dawnings open little by little into the full light.
    • Reply upon being asked how he made his discoveries, as quoted in Newton Tercentenary Celebrations: 15-19 July 1946 (1947) by The Royal Society; also in Nature (4 September 1965)

  • Truth is ever to be found in simplicity, and not in the multiplicity and confusion of things.
    • Rules for methodizing the Apocalypse, Rule 9, from a manuscript published in The Religion of Isaac Newton (1974) by Frank E. Manuel, p. 120, as quoted in Socinianism And Arminianism : Antitrinitarians, Calvinists, And Cultural Exchange in Seventeenth-Century Europe (2005) by Martin Mulsow, Jan Rohls, p. 273.
    • Variant: Truth is ever to be found in the simplicity, and not in the multiplicity and confusion of things.
      • As quoted in God in the Equation : How Einstein Transformed Religion (2002) by Corey S. Powell, p. 29

  • It is the perfection of God's works that they are all done with the greatest simplicity. He is the God of order and not of confusion. And therefore as they would understand the frame of the world must endeavor to reduce their knowledge to all possible simplicity, so must it be in seeking to understand these visions.
    • Rules for methodizing the Apocalypse, Rule 9, from a manuscript published in The Religion of Isaac Newton (1974) by Frank E. Manuel, p. 120, quoted in Never at Rest: A Biography of Isaac Newton (1983) by Richard S. Westfall, p. 326, in Fables of Mind: An Inquiry Into Poe's Fiction (1987) by Joan Dayan, p. 240, and in Everything Connects: In Conference with Richard H. Popkin (1999) by Richard H. Popkin, James E. Force, and David S. Katz, p. 124

  • If I had stayed for other people to make my tools and things for me, I had never made anything.
    • This is from an anecdote found in The Foundations of Newton’s Alchemy, or "The Hunting of the Greene Lyon" (1975) by Betty Jo Teeter Dobbs :
Newton’s reflecting telescope was an extraordinary achievement. His first telescope was about 6 inches long with a 2 inch mirror and magnified by forty times. He was proud of his handiwork even sixty years later, when Conduitt reports a conversation: "I asked him where he had it made, he said he made it himself, and when I asked him where he got his tools said he made them himself and laughing added if I had stayed for other people to make my tools and things for me, I had never made anything..."

  • In the absence of any other proof, the thumb alone would convince me of God's existence.
    • As quoted in Fearfully and Wonderfully Made (1987) by Philip Yancey and Paul W. Brand, p. 161; also in Wisdom (2002) by Des MacHale

  • God created everything by number, weight and measure.
    • As quoted in Symmetry in Plants (1998) by Roger V. Jean and Denis Barabé, p. xxxvii, a translation of a Latin phrase he wrote in a student's notebook, elsewhere given as Numero pondere et mensura Deus omnia condidit. This is similar to Latin statements by Thomas Aquinas, and even more ancient statements of the Greek philosopher Pythagoras.

Philosophiae Naturalis Principia Mathematica (1687)

  • The ancients considered mechanics in a twofold respect; as rational, which proceeds accurately by demonstration, and practical. To practical mechanics all the manual arts belong, from which mechanics took its name. But as artificers do not work with perfect accuracy, it comes to pass that mechanics is so distinguished from geometry, that what is perfectly accurate is called geometrical; what is less so is called mechanical. But the errors are not in the art, but in the artificers. He that works with less accuracy is an imperfect mechanic: and if any could work with perfect accuracy, he would be the most perfect mechanic of all; for the description of right lines and circles, upon which geometry is founded, belongs to mechanics. Geometry does not teach us to draw these lines, but requires them to be drawn; for it requires that the learner should first be taught to describe these accurately, before he enters upon geometry; then it shows how by these operations problems may be solved.
    • Preface (8 May 1686)

  • Our design, not respecting arts, but philosophy, and our subject, not manual, but natural powers, we consider chiefly those things which relate to gravity, levity, elastic force, the resistance of fluids, and the like forces, whether attractive or impulsive; and therefore we offer this work as mathematical principles of philosophy; for all the difficulty of philosophy seems to consist in this — from the phenomena of motions to investigate the forces of nature, and then from these forces to demonstrate the other phenomena...
    • Preface

  • I wish we could derive the rest of the phenomena of nature by the same kind of reasoning from mechanical principles; for I am induced by many reasons to suspect that they may all depend upon certain forces by which the particles of bodies, by some causes hitherto unknown, are either mutually impelled towards each other, and cohere in regular figures, or are repelled and recede from each other; which forces being unknown, philosophers have hitherto attempted the search of nature in vain; but I hope the principles here laid down will afford some light either to that or some truer method of philosophy.
    • Preface

  • I do not define time, space, place, and motion, as being well known to all. Only I must observe, that the common people conceive those quantities under no other notions but from the relation they bear to sensible objects. And thence arise certain prejudices, for the removing of which it will be convenient to distinguish them into absolute and relative, true and apparent, mathematical and common.
    • Definitions - Scholium

  • It is indeed a matter of great difficulty to discover, and effectually to distinguish, the true motions of particular bodies from the apparent; because the parts of that immovable space, in which those motions are performed, do by no means come under the observation of our senses. Yet the thing is not altogether desperate; for we have some arguments to guide us, partly from the apparent motions, which are the differences of the true motions; partly from the forces, which are the causes and effects of the true motions.
    • Definitions - Scholium

  • We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.
    • "Rules of Reasoning in Philosophy" : Rule I

  • Every body continues in its state of rest, or of uniform motion in a right line, unless it is compelled to change that state by forces impressed upon it.
    • Laws of Motion, I

  • The alternation of motion is ever proportional to the motive force impressed; and is made in the direction of the right line in which that force is impressed.
    • Laws of Motion, II

  • To every action there is always opposed an equal reaction; or, the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.
    • Laws of Motion, III

  • Hypotheses non fingo.
    • I frame no hypotheses.
      • A famous statement in the "General Scholium" of the third edition, indicating his belief that the law of universal gravitation was a fundamental empirical law, and that he proposed no hypotheses on how gravity could propagate.
    • Variant translation: I feign no hypotheses.
    • I have not as yet been able to discover the reason for these properties of gravity from phenomena, and I do not feign hypotheses. For whatever is not deduced from the phenomena must be called a hypothesis; and hypotheses, whether metaphysical or physical, or based on occult qualities, or mechanical, have no place in experimental philosophy. In this philosophy particular propositions are inferred from the phenomena, and afterwards rendered general by induction.

Opticks (1704)

There were several editions of Opticks in English and in Latin made in Newtons lifetime, including expansions of the original 16 "Queries" to eventually number 31.

  • To make way for the regular and lasting Motions of the Planets and Comets, it's necessary to empty the Heavens of all Matter, except perhaps some very thin Vapours, Steams or Effluvia, arising from the Atmospheres of the Earth, Planets and Comets, and from such an exceedingly rare Æthereal Medium ... A dense Fluid can be of no use for explaining the Phænomena of Nature, the Motions of the Planets and Comets being better explain'd without it. It serves only to disturb and retard the Motions of those great Bodies, and make the frame of Nature languish: And in the Pores of Bodies, it serves only to stop the vibrating Motions of their Parts, wherein their Heat and Activity consists. And as it is of no use, and hinders the Operations of Nature, and makes her languish, so there is no evidence for its Existence, and therefore it ought to be rejected. And if it be rejected, the Hypotheses that Light consists in Pression or Motion propagated through such a Medium, are rejected with it.
    And for rejecting such a Medium, we have the authority of those the oldest and most celebrated philosophers of ancient Greece and Phoenicia, who made a vacuum and atoms and the gravity of atoms the first principles of their philosophy, tacitly attributing Gravity to some other Cause than dense Matter. Later Philosophers banish the Consideration of such a Cause out of natural Philosophy, feigning Hypotheses for explaining all things mechanically, and referring other Causes to Metaphysicks: Whereas the main Business of natural Philosophy is to argue from Phenomena without feigning Hypotheses, and to deduce Causes from Effects, till we come to the very first Cause, which certainly is not mechanical.
    • Query 28 : Are not all Hypotheses erroneous in which Light is supposed to consist of Pression or Motion propagated through a fluid medium?

  • What is there in places empty of matter? and Whence is it that the sun and planets gravitate toward one another without dense matter between them? Whence is it that Nature doth nothing in vain? and Whence arises all that order and beauty which we see in the world? To what end are comets? and Whence is it that planets move all one and the same way in orbs concentrick, while comets move all manner of ways in orbs very excentrick? and What hinders the fixed stars from falling upon one another?
    • Query 28 : Are not all Hypotheses erroneous in which Light is supposed to consist of Pression or Motion propagated through a fluid medium?

  • The changing of bodies into light, and light into bodies, is very conformable to the course of Nature, which seems delighted with transmutations.
    • Query 30 : Are not gross bodies and light convertible into one another, and may not bodies receive much of their activity from the particles of light which enter into their composition?

  • It seems probable to me that God, in the beginning, formed matter in solid, massy, hard, impenetrable, moveable particles, of such sizes and figures, and with such other properties, and in such proportions to space, as most conduced to the end for which He formed them; and that these primitive particles, being solids, are incomparably harder than any porous bodies compounded of them, even so very hard as never to wear or break in pieces; no ordinary power being able to divide what God had made one in the first creation. While the particles continue entire, they may compose bodies of one and the same nature and texture in all ages: but should they wear away or break in pieces, the nature of things depending on them would be changed.
    • Query 31 : Have not the small particles of bodies certain powers, virtues, or forces, by which they act at a distance, not only upon the rays of light for reflecting, refracting, and inflecting them, but also upon one another for producing a great part of the Phenomena of nature?

Board of Longitude

  • One [method] is by a Watch to keep time exactly. But, by reason of the motion of the Ship, the Variation of Heat and Cold, Wet and Dry, and the Difference of Gravity in different Latitudes, such a watch hath not yet been made.
    • Written in remarks to the 1714 Longitude committee; quoted in Longitude (1995) by Dava Sobel, p. 52 (i998 edition) ISBN 1-85702-571-7),

  • A good watch may serve to keep a recconing at Sea for some days and to know the time of a Celestial Observ[at]ion: and for this end a good Jewel watch may suffice till a better sort of Watch can be found out. But when the Longitude at sea is once lost, it cannot be found again by any watch.
    • Letter to Josiah Burchett (1721), quoted in Longitude (1995) by Dava Sobel, p. 60

A short Schem of the true Religion

Undated manuscript : Keynes Ms. 7: '"A short Schem of the true Religion'"

  • Religion is partly fundamental & immutable partly circumstantial & mutable. The first was the Religion of Adam, Enoch, Noah, Abraham Moses Christ & all the saints & consists of two parts our duty towards God & our duty towards man or piety & righteousness, piety which I will here call Godliness & Humanity.

  • Godliness consists in the knowledge love & worship of God, Humanity in love, righteousness & good offices towards man.
    • Of Godliness

  • Atheism is so senseless & odious to mankind that it never had many professors. Can it be by accident that all birds beasts & men have their right side & left side alike shaped (except in their bowells) & just two eyes & no more on either side the face & just two ears on either side the head & a nose with two holes & no more between the eyes & one mouth under the nose & either two fore leggs or two wings or two arms on the sholders & two leggs on the hipps one on either side & no more? Whence arises this uniformity in all their outward shapes but from the counsel & contrivance of an Author? Whence is it that the eyes of all sorts of living creatures are transparent to the very bottom & the only transparent members in the body, having on the outside an hard transparent skin, & within transparent juyces with a crystalline Lens in the middle & a pupil before the Lens all of them so truly shaped & fitted for vision, that no Artist can mend them? Did blind chance know that there was light & what was its refraction & fit the eys of all creatures after the most curious manner to make use of it? These & such like considerations always have & ever will prevail with man kind to believe that there is a being who made all things & has all things in his power & who is therfore to be feared.
    • Of Atheism

  • Idolatry is a more dangerous crime because it is apt by the authority of Kings & under very specious pretenses to insinuate it self into mankind. Kings being apt to enjoyn the honour of their dead ancestors: & it seeming very plausible to honour the souls of Heroes & Saints & to believe that they can heare us & help us & are mediators between God & man & reside & act principally in the temples & statues dedicated to their honour & memory? And yet this being against the principal part of religion is in scripture condemned & detested above all other crimes. The sin consists first in omitting the service of the true God.
    • Of Idolatry

  • The other part of the true religion is our duty to man. We must love our neighbour as our selves, we must be charitable to all men for charity is the greatest of graces, greater then even faith or hope & covers a multitude of sins. We must be righteous & do to all men as we would they should do to us.
    • Of Humanity

  • No man hath seen God at any time, if we love one another God dwelleth in us. — If a man say I love God & hateth his brother he is a liar: for he that loveth not his brother whom he hath seen how can he love God whom he hath not seen?
    • Of Humanity


  • Atheism is so senseless. When I look at the solar system, I see the earth at the right distance from the sun to receive the proper amounts of heat and light. This did not happen by chance.
    • As quoted in What If Jesus Had Never Been Born (1994) by D. James Kennedy and Jerry Newcombe, p. 100; also in Lord Of All : Developing a Christian World-and-life View (2005) by the same authors.
    • "Atheism is so senseless" is a portion of a statement Newton is known to have made (which is posted above in "A short Schem of the true Religion"), but there have been no occurrences of the rest of this statement yet located prior to 1994. Newton is known to have been profoundly religious, but the tone, style and arguments simply do not seem to match any which Newton is likely to have used. The argument that Earth is the "right distance from the sun" and even the idea that its placement might have possibly been "by chance" are rather modern in tone, and strongly imply some evolutionary assumptions which Newton would not likely have even considered.


  • Tact is the art of making a point without making an enemy.
    • Actually a statement by American advertising executive and author Howard W. Newton (1903 - 1951)

Quotes about Newton

  • He bought a book of Iudicial Astrology out of a curiosity to see what there was in that science & read in it till he came to a figure of the heavens which he could not understand for want of being acquainted with Trigonometry, & to understand the ground of that bought an English Euclid with an Index of all the problems at the end of it & only turned to two or three which he thought necessary for his purpose & read nothing but the titles of them finding them so easy & self evident that he wondered any body would be at the pains of writing a demonstration of them & laid Euclid aside as a trifling book, & was soon convinced of the vanity & emptiness of the pretended science of Iudicial astrology.
    • An account by John Conduitt, Newton's assistant and his niece's husband, of Newton saying that, as a young student, he had read a book on astrology and was not impressed with it. Also quoted in The Mathematical Papers of Isaac Newton (1967) by D.T. Whiteside, M.A. Hoskin and A. Prag, Vol. 1, pp. 15-19.

  • His peculiar gift was the power of holding continuously in his mind a purely mental problem until he had seen it through.

  • Newton was not the first of the age of reason. He was the last of the magicians, the last of the Babylonians and Sumerians, the last great mind that looked out on the visible and intellectual world with the same eyes as those who began to build our intellectual inheritance rather less than 10 000 years ago.
    • John Maynard Keynes, Address to the Royal Society Club (1942), as quoted in A Dictionary of Scientific Quotations (1977) by Alan L. MacKay, p.140

  • Nature and nature's laws lay hid in night;
    God said "Let Newton be" and all was light.

  • There is a traditional story about Newton: as a young student, he began the study of geometry, as was usual in his time, with the reading of the Elements of Euclid. He read the theorems, saw that they were true, and omitted the proofs. He wondered why anybody should take pains to prove things so evident. Many years later, however, he changed his opinion and praised Euclid. The story may be authentic or not, ...

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