The sciences of only one nation, the Greeks, have come down to us, because they were translated through Al-Ma'mun's efforts. He was successful in this direction because he had many translators at his disposal and spent much money in this connection.

The 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.

The sciences of only one nation, the Greeks, have come down to us, because they were translated through Al-Ma'mun's efforts. He was successful in this direction because he had many translators at his disposal and spent much money in this connection.

Businesses owned by responsible and organized merchants shall eventually surpass those owned by wealthy rulers.

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.

Habits are qualities of the soul.

At the beginning of a dynasty, taxation yields a large revenue from small assessments. At the end of the dynasty, taxation yields a small revenue from large assessments.