“عندما يكون شىء ما متطرفاً أو مفرطاً فى حضوره و قوته فإنه سيكون، بالنسبة للخيال، هاوية سحيقة، يخاف الخيال أن يفقد ذاته فيها”

“...new prejudices will serve as well as old ones to harness the great unthinking masses.For this enlightenment, however, nothing is required but freedom, and indeed the most harmless among all the things to which this term can properly be applied. It is the freedom to make public use of one's reason at every point. But I hear on all sides, 'Do not argue!' The Officer says: 'Do not argue but drill!' The tax collector: 'Do not argue but pay!' The cleric: 'Do not argue but believe!' Only one prince in the world says, 'Argue as much as you will, and about what you will, but obey!' Everywhere there is restriction on freedom.”

“Denken zonder ervaring is leeg, maar ervaring zonder denken is blind.”

“A categorical imperative would be one which represented an action as objectively necessary in itself, without reference to any other purpose.”

“How then is perfection to be sought? Wherein lies our hope? In education, and in nothing else.”

“It is of great consequence to have previously determined the concept that one wants to elucidate through observation before questioning experience about it; for one finds in experience what one needs only if one knows in advance what to look for.”

“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.”