“The schematicism by which our understanding deals with the phenomenal world ... is a skill so deeply hidden in the human soul that we shall hardly guess the secret trick that Nature here employs.”

“The light dove, in free flight cutting through the air the resistance of which it feels, could get the idea that it could do even better in airless space. Likewise, Plato abandoned the world of the senses because it posed so many hindrances for the understanding, and dared to go beyond it on the wings of the ideas, in the empty space of pure understanding.”

“Skepticism is thus a resting-place for human reason, where it can reflect upon its dogmatic wanderings and make survey of the region in which it finds itself, so that for the future it may be able to choose its path with more certainty. But it is no dwelling-place for permanent settlement. Such can be obtained only through perfect certainty in our knowledge, alike of the objects themselves and of the limits within which all our knowledge of objects is enclosed.”

“All rational knowledge is either material, and concerns some objects, or formal, and is occupied only with the form of understanding and reason itself and with the universal rules of thinking, without regard to distinctions among objects. formal philosophy is called logic. Material philosophy, however, which has to do with definite object objects and the laws to which they are subject, is divided into two parts. This is because these laws are either laws of nature or laws of freedom. The science of the former is called physics, and that of the latter ethics. The former is also called theory of nature and the latter theory of morals.”

“As nature has uncovered from under this hard shell the seed for which she most tenderly cares - the propensity and vocation to free thinking - this gradually works back upon the character of the people, who thereby gradually become capable of managing freedom; finally, it affects the principles of government, which finds it to its advantage to treat men, who are now more than machines, in accordance with their dignity.”

“Laziness and cowardice are the reasons why so great a portion of mankind, after nature has long since discharged them from external direction (naturaliter maiorennes), nevertheless remains under lifelong tutelage, and why it is so easy for others to set themselves up as their guardians. It is so easy not to be of age. If I have a book which understands for me, a pastor who has a conscience for me, a physician who decides my diet, and so forth, I need not trouble myself. I need not think, if I can only pay - others will easily undertake the irksome work for me.That the step to competence is held to be very dangerous by the far greater portion of mankind...”

“All our knowledge begins with the senses, proceeds then to the understanding, and ends with reason. There is nothing higher than reason.”