“Genius is fostered by energy.”
Suggested to be from Pro Caelio (ch. xix, sec. 45: "...in that branch of study you saw not only his genius shine forth, which frequently, even when it is not nourished by industry, still produces great effects by its own natural vigour...")
Disputed
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Marcus Tullius Cicero 180
Roman philosopher and statesman -106–-43 BCRelated quotes

“Ours is the faith of the apostles, handed down by St Thomas” http://www.30giorni.it/articoli_id_78071_l3.htm (2011)

leadersmag.com http://www.leadersmag.com/issues/2012.3_Jul/Women%20Leaders/LEADERS-Irina-Bokova-UNESCO.html.

"Fallen Western Star," http://www.danagioia.net/essays/ewestern.htm Denver Quarterly (Fall 1998)
Essays

“Perhaps genius alone understands genius fully.”
Sometimes translated as: Perhaps only genius fully understands genius
Original: Vielleicht versteht nur der Genius den Genius ganz, Robert Schumann, Advice to Young Musicians, translation of Musikalische Haus- und Lebens-Regeln, translated by Henry Hugo Pierson, Leipsic & New York: J. Schuberth & Co., 1860.

Le génie enfante, le goût conserve. Le goût est le bon sens du génie; sans le goût, le génie n'est qu'une sublime folie.
François-René de Chateaubriand, in "Essai sur la littérature anglaise (1836): Modèles classiques http://visualiseur.bnf.fr/CadresFenetre?O=NUMM-101390&M=tdm.
Misattributed
“The only genius that's worth anything is the genius for hard work.”

“Genius is always sufficiently the enemy of genius by over influence.”
1830s, The American Scholar http://www.emersoncentral.com/amscholar.htm (1837)