God, the supreme being, is neither circumscribed by space, nor touched by time; he cannot be found in a particular direction, and his essence cannot change. The secret conversation is thus entirely spiritual; it is a direct encounter between God and the soul, abstracted from all material constraints.
AvicennaMedicine considers the human body as to the means by which it is cured and by which it is driven away from health.
AvicennaThe knowledge of anything, since all things have causes, is not acquired or complete unless it is known by its causes.
AvicennaMountains have been formed by one [or other] of the causes of the formation of stone, most probably from agglutinative clay which slowly dried and petrified during ages of which we have no record. It seems likely that this habitable world was in former days uninhabitable and, indeed, submerged beneath the ocean. Then, becoming exposed little by little, it petrified in the course of ages.
Avicenna