Ibn Sīnā refers to the secondary education stage of maktab schooling as a period of specialisation when pupils should begin to acquire manual skills, regardless of their social status. He writes that children after the age of 14 should be allowed to choose and specialise in subjects they have an interest in, whether it was reading, manual skills, literature, preaching, medicine, geometry, trade and commerce, craftsmanship, or any other subject or profession they would be interested in pursuing for a future career. He wrote that this was a transitional stage and that there needs to be flexibility regarding the age in which pupils graduate, as the student's emotional development and chosen subjects need to be taken into account.