Geometry enlightens the intellect and sets one's mind right. All of its proofs are very clear and orderly. It is hardly possible for errors to enter into geometrical reasoning, because it is well arranged and orderly. Thus, the mind that constantly applies itself to geometry is not likely to fall into error. In this convenient way, the person who knows geometry acquires intelligence.
Ibn KhaldunWhen incentive to acquire and obtain property is gone, people no longer make efforts to acquire any... Those who infringe upon property rights commit an injustice... If this occurs repeatedly, all incentives to cultural enterprise are destroyed and they cease utterly to make an effort. This leads to destruction and ruin of civilization.
Ibn KhaldunThe term of life of a dynasty does not normally exceed three generations. For in the first generation are still preserved the characteristic features of rough, uncivilized rural life, such as hard conditions of life, courage, ferocity, and partnership in authority. Therefore the strength of the 'Asabiya is maintained.
Ibn KhaldunAll the sciences came to exist in Arabic. The systematic works on them were written in Arabic writing.
Ibn Khaldun