Isaac Newton Quotes: Sources, Meanings & Themes
Browse quotations by Isaac Newton with named works, context notes, meanings and recurring themes.
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“If I have seen farther, it is by standing on the shoulders of giants.”
Meaning & context
Newton credits earlier and contemporary intellectual work as part of what made his own advances possible, framing discovery as cumulative rather than wholly solitary.
Source details
Newton to Robert Hooke, Cambridge, February 5, 1675/76, represented by the Newton Project normalized transcription. The historical letter uses older spelling; this record follows the project’s normalized “farther” and “shoulders of giants” wording.
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“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?”
Meaning & context
Newton poses a speculative question about relationships between matter and light, illustrating how the later Queries of Opticks use open questions to push beyond the book’s demonstrated optical results.
Source details
Opticks, Query 30, represented from the fourth corrected edition text (1730) by Inters.org. Newton states this as a question within his historical natural-philosophy speculation; it is not presented as a modern account of particle physics or matter–energy conversion.
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“I frame no hypotheses; for whatever is not deduced from the phenomena is to be called an hypothesis.”
Meaning & context
Newton distinguishes conclusions inferred from observed phenomena from explanations he regards as unsupported speculation within the methodological argument of the General Scholium.
Source details
Philosophiæ Naturalis Principia Mathematica, General Scholium, added to the second edition in 1713; represented by the 1846 Andrew Motte English translation on Wikisource. “I frame no hypotheses” is kept inside Newton’s specific discussion of gravity and experimental philosophy rather than treated as a blanket prohibition on hypotheses in modern science.