“ It frequently happens that a man delivers his opinions with so much boldness and assurance, that he appears to be under no apprehension as to the possibility of his being in error. ”
 Immanuel Kant, Critique of Pure Reason (1791). copy citation

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Author Immanuel Kant
Source Critique of Pure Reason
Topic self-assurance error
Date 1791
Language English
Reference
Note Translated by J. M. D. Meiklejohn
Weblink http://www.gutenberg.org/files/4280/4280-h/4280-h.htm

Context

“Such a belief, contingent indeed, but still forming the ground of the actual use of means for the attainment of certain ends, I term Pragmatical belief. The usual test, whether that which any one maintains is merely his persuasion, or his subjective conviction at least, that is, his firm belief, is a bet. It frequently happens that a man delivers his opinions with so much boldness and assurance, that he appears to be under no apprehension as to the possibility of his being in error. The offer of a bet startles him, and makes him pause. Sometimes it turns out that his persuasion may be valued at a ducat, but not at ten. For he does not hesitate, perhaps, to venture a ducat, but if it is proposed to stake ten, he immediately becomes aware of the possibility of his being mistaken—a possibility which has hitherto escaped his observation.” source