Rudolf Pfeiffer, History of Classical Scholarship 1300-1850 (Chp. II):
“Poggio never strove after a Ciceronian style or even a grammatically correct Latin; he treated Latin as if it were a living language, and because of that we see him in the last years of his life at feud with the leading spirit of the next generation, Lorenzo Valla.
One day in 1451 Poggio found in a copy of the collection of his letters to Niccoli, of which he was very proud, some critical and ironical comments upon his Latinity, scrawled in the margin by a pupil of Valla’s; he got so angry with Valla, whom he suspected of being the author, that he tried to have him murdered, a dramatic refutation, had he succeeded, of Schopenhauer’s saying that ‘the history of . . . learning and art’ (in contrast to the universal history of the world) ‘is always going on . . . guiltless and without bloodshed.’ But Poggio finally confined himself to a form of retaliation more appropriate in a scholar, a literary invective. Valla, no less pugnacious, replied, and a war of pamphlets, five from each side, ensued, the arguments of which were of a general importance far beyond the trivial cause.”