Demosthenes was apt at combining abruptness with the extended period, brevity with breadth. Hence, his style harmonises with his fervent commitment. His language is simple and natural, never far-fetched or artificial. According to Jebb, Demosthenes was a true artist who could make his art obey him. For his part, Aeschines stigmatised his intensity, attributing to his rival strings of absurd and incoherent images. Dionysius stated that Demosthenes' only shortcoming is the lack of humour, although Quintilian regards this deficiency as a virtue. In a now lost letter, Cicero, though an admirer of the Athenian orator, claimed that occasionally Demosthenes "nods", and elsewhere Cicero also argued that, although he is pre-eminent, Demosthenes sometimes fails to satisfy his ears.* D.C. Innes, "Longinus and Caecilius", 262 (note 10).</ref> The main criticism of Demosthenes' art, however, seems to have rested chiefly on his known reluctance to speak ; he often declined to comment on subjects he had not studied beforehand. However, he gave the most elaborate preparation to all his speeches and, therefore, his arguments were the products of careful study. He was also famous for his caustic wit.