1675年出版的《解释光属性的假说》（An Hypothesis explaining the Properties of Light）中，牛顿認為粒子间力的传递是透過以太进行的。不過牛顿在与神智學家亨利·莫爾接触后重新燃起了对炼金术的兴趣，並改用源於赫密斯神智學中粒子相吸互斥思想的神秘力量來解釋，替换了先前假設以太存在的看法。拥有许多牛顿炼金术著作的經濟學大師约翰·梅纳德·凯恩斯曾说：“牛顿不是理性時代的第一人，他是最后的一位炼金术士。”[10]但牛顿對炼金术的兴趣卻與他对科学的贡献息息相關[11]，而且在那个时代炼金术与科学也還没有明确的区別。如果他没有依靠神秘学思想来解释穿过真空的超距作用，他可能也不會发展出他的重力理论。
同時代的作家威廉·斯蒂克利牧師在他的《艾薩克·牛頓爵士生平回憶錄》中记录了1726年4月15日他在肯辛顿与牛顿的一次谈话[39]，在该次谈话中，牛顿回忆了“从前，萬有引力的概念进入了他的脑海，由於苹果的下落引起了他的思考，他心中想到，为什么苹果总会垂直地落在地上，为什么不能向侧邊或者向上移動，而是不斷地朝向地球的中心。”[40]相似的说法还出现在伏尔泰的著述《Essay on Epic Poetry》（1727）中：“艾萨克·牛顿爵士在他的花园里散步，首次想到了他的引力体系，接着便看见一颗苹果从树上掉下。”[41]
《简编年史》（Short Chronicle）、《世界之体系》（The System of the World）、《光学讲稿》（Optical Lectures）、《古王国年表，修订》（The Chronology of Ancient Kingdoms, Amended）和De mundi systemate在他死后的1728年出版。
《两处著名圣经讹误的历史变迁》(An Historical Account of Two Notable Corruptions of Scripture，1754)
牛顿在世时，欧洲通行有两种不同的历法：在英国和西欧的部分地区仍使用儒略曆或称“旧历”，某些其他地方则已改用格里历或称“新历”。在牛顿出生时，格里历要比儒略历快10天：因此牛顿出生于儒略历1642年的圣诞节，或者是格里历1643年的1月4日。此外，在1752年英国改用格里历前，英格兰新年开始于3月25日（道成肉身纪念日，the anniversary of the Incarnation）而不是1月1日，因此牛頓死亡時，儒略曆尚未跨年，但格里曆已跨年。除非另有说明，本文中其他的日期均采用儒略历。
Cohen, I.B. Dictionary of Scientific Biography [科学传记辞典]. 纽约: Charles Scribner's Sons. 1970: 11卷，43页 （英语）. Threatening my father and mother Smith to burn them and the house over them...
Bell, E.T. Men of Mathematics [大数学家] Touchstone edition. 纽约: Simon & Schuster. 1986: 91－2页 [1937] （英语）. Newton began his schooling in the village schools and was later sent to The King's School, Grantham, where he became the top student in the school. At King's, he lodged with the local apothecary, William Clarke and eventually became engaged to the apothecary's stepdaughter, Anne Storer, before he went off to the University of Cambridge at the age of 19. As Newton became engrossed in his studies, the romance cooled and Miss Storer married someone else. It is said he kept a warm memory of this love, but Newton had no other recorded 'sweet-hearts' and never married. 引文格式1维护：冗余文本 (link)
Dobbs, J.T. Newton's Alchemy and His Theory of Matter. Isis. December 1982, 73 (4): p. 523. 引文格式1维护：冗余文本 (link) quoting Opticks.原文为：“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 their Composition?”
Keynes, John Maynard. Newton, The Man. The Collected Writings of John Maynard Keynes Volume X [凯恩斯作品集，卷X]. MacMillan St. Martin's Press. 1972: pp. 363–364 （英语）. Newton was not the first of the age of reason: he was the last of the magicians. 引文格式1维护：冗余文本 (link)
Westfall, Richard S. Never at Rest: A Biography of Isaac Newton [永不止息：艾萨克·牛顿传]. 剑桥大学: 剑桥大学出版社. 1983: pp. 530–1 [1980] （英语）. 引文格式1维护：冗余文本 (link)提到了牛顿显然抛弃了他的炼金术研究。
原文为：“Nature and nature's laws lay hid in night; God said "Let Newton be" and all was light.”译文取自：Koyré, Alexandre. 《牛顿研究》. 张卜天译 第1版. 北京: 北京大学出版社. 2003年1月: 13. ISBN 7-301-06093-9（中文（简体））.
Tiner, J.H. Isaac Newton: Inventor, Scientist and Teacher [艾萨克·牛顿：发明家、科学家和教师]. 美国密歇根州米尔福德市: Mott Media. 1975 （英语）. Gravity explains the motions of the planets, but it cannot explain who set the planets in motion. God governs all things and knows all that is or can be done.
Haakonssen, Knud. The Enlightenment, politics and providence: some Scottish and English comparisons. Martin Fitzpatrick ed. (编). Enlightenment and Religion: Rational Dissent in eighteenth-century Britain [启蒙运动与宗教：十八世纪英国的理性异教者]. 剑桥: 剑桥大学出版社. : 64页 （英语）.
Principia, Book III; cited in; Newton’s Philosophy of Nature: Selections from his writings, p. 42, ed. H.S. Thayer, Hafner Library of Classics, NY, 1953.
A Short Scheme of the True Religion, manuscript quoted in Memoirs of the Life, Writings and Discoveries of Sir Isaac Newton by Sir David Brewster, Edinburgh, 1850; cited in; ibid, p. 65.
Marquard, Odo. "Burdened and Disemburdened Man and the Flight into Unindictability," in Farewell to Matters of Principle. Robert M. Wallace trans.伦敦：牛津大学出版社，1989。
Papers Show Isaac Newton's Religious Side, Predict Date of Apocalypse. The Associated Press. 2007-06-19 [2015-01-29]. （原始内容存档于2007-06-29） （英语）.原文为：“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.”
Don Juan (1821), Canto 10, Verse I. In Jerome J. McGann (ed.), Lord Byron: The Complete Poetical Works (1986), Vol. 5, 437.“When Newton saw an apple fall, he found / In that slight startle from his contemplation -- / 'Tis said (for I'll not answer above ground / For any sage's creed or calculation) -- / A mode of proving that the earth turn'd round / In a most natural whirl, called "gravitation;" /
And this is the sole mortal who could grapple, / Since Adam, with a fall or with an apple.”
Conduitt, John. Keynes Ms. 130.4:Conduitt's account of Newton's life at Cambridge. Newtonproject. [2006-08-30]. （原始内容存档于2006-10-04） （英语）. In the year 1666 he retired again from Cambridge to his mother in Lincolnshire. Whilst he was pensively meandering in a garden it came into his thought that the power of gravity (which brought an apple from a tree to the ground) was not limited to a certain distance from earth, but that this power must extend much further than was usually thought. Why not as high as the Moon said he to himself & if so, that must influence her motion & perhaps retain her in her orbit, whereupon he fell a calculating what would be the effect of that supposition.
“when formerly, the notion of gravitation came into his mind. It was occasioned by the fall of an apple, as he sat in contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to himself. Why should it not go sideways or upwards, but constantly to the earth's centre.”
Wilson, Fred L. History of Science: Newton [科学史：牛顿]. Fred Wilson's Physics Web. [2015-01-29]. （原始内容存档于2007-06-30） （英语）. citing: Delambre, M. "Notice sur la vie et les ouvrages de M. le comte J. L. Lagrange," Oeuvres de Lagrange I. Paris, 1867, p. xx.原文为“the most fortunate, for we cannot find more than once a system of the world to establish.”
Memoirs of the Life, Writings, and Discoveries of Sir Isaac Newton (1855) by Sir David Brewster (Volume II. Ch. 27)。原文为“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.”
「牛頓」重定向至此。关于其他用法，请见「牛頓 (消歧义)」。
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英格蘭林肯郡伍尔索普庄园
英國伦敦肯辛顿
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英格蘭王國議會議員
英語维基文库中与本条目相关的原始文献：艾薩克·牛頓爵士生平回憶錄）一書的描述，斯蒂克利在牛頓死後曾訪問過文森特夫人，也就是當年牛頓的戀人斯托勒小姐。文森特夫人的名字叫做凯瑟琳，而不是安妮，安妮是她的妹妹[b]，而且夫人仅表示牛顿當年寄宿時對她只不過是「懷有情愫」的程度而已。
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