
The Notebooks of Leonardo da Vinci (1883), XIX Philosophical Maxims. Morals. Polemics and Speculations.
Variant translations:
Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory.
As quoted in The Book of Unusual Quotations (1957) by Rudolf Flesch, p. 12
Any one who in discussion relies upon authority uses, not his understanding, but rather his memory.
The Notebooks of Leonardo da Vinci (1883), I Prolegomena and General Introduction to the Book on Painting
The Notebooks of Leonardo da Vinci (1883), XIX Philosophical Maxims. Morals. Polemics and Speculations.
“Selected Aphorisms from the Athenaeum (1798)”, Dialogue on Poetry and Literary Aphorisms, Ernst Behler and Roman Struc, trans. (Pennsylvania University Press:1968) #96
Athenäum (1798 - 1800)
Letter to Thomas Jefferson Hogg (3 January 1811)
Quoted in Salazar: Biographical Study - page 368; of Franco Nogueira - Published by Atlantis Publishing, 1977
“The author discusses valueless measures in pointless spaces.”
Proposal for a humorous first sentence to a review of a mathematical paper, rejected by editors.
I Want to be a Mathematician: An Automathography (1985)
“...whoever is not against us is for us.”
9:40 http://www.biblegateway.com/passage/?search=Mark%209:40;&version=31;
New Testament, Gospel of Mark