Everyone is prejudiced in favor his own powers of discernment, and will always find an argument most convincing if it leads to the conclusion he has reached for himself; everyone must then be given something he can grasp and recognize as his own idea.

Pliny the Younger (c. 61-c. 113) Roman politician, writer [Gaius Plinius Caecilius Secundus]

Letters, Book 1, Letter 20 [tr. Radice (1963)]