 In every suddenly appearing conflict between what is perceived and what is thought, what is perceived is always unquestionably right; for it is not subject to error at all, requires no confirmation from without, but answers for itself. … The victory of knowledge of perception over thought affords us pleasure. For perception is the original kind of knowledge inseparable from animal nature, in which everything that gives direct satisfaction to the will presents itself. It is the medium of the present, of enjoyment and gaiety; moreover it is attended with no exertion. With thinking the opposite is the case: it is the second power of knowledge, the exercise of which always demands some, and often considerable exertion. Besides, it is the conceptions of thought that often oppose the gratification of our immediate desires, for, as the medium of the past, the future, and of seriousness, they are the vehicles of our fears, our repentance, and all our cares. It must therefore be diverting to us to see this strict, untiring, troublesome governess, the reason, for once convicted of insufficiency. On this account then the mien or appearance of laughter is very closely related to that of joy (Supplement to Book I, Ch. 8).