Art, science and the teaching thereof are free. The state guarantees their protection and takes part in fostering them. ARTICLE 143 The education of the young shall be provided for through public institutions. In their establishment the Commonwealth, States and municipalities co-operate. The training of teachers shall be regulated in a uniform manner for the Commonwealth according to the generally recognized principles of higher education. The teachers in the public schools have the rights and duties of state officers. ARTICLE 144 The entire school system is under the supervision of the state; it may grant a share therein to the municipalities. The supervision of schools will be exercised by technically trained officers who must devote their time principally to this duty. ARTICLE 145 Attendance at school is obligatory. This obligation is discharged by attendance at the elementary schools for at least eight school years and at the continuation schools until the completion of the eighteenth year. Instruction and school supplies in the elementary and continuation schools are free. ARTICLE 146 The public school system shall be systematically organized. Upon a foundation of common elementary schools the system of secondary and higher education is erected. The development of secondary and higher education shall be determined in accordance with the needs of all kinds of occupations, and the acceptance of a child in a particular school shall depend upon his qualifications and inclinations, not upon the economic and social position or the religion of his parents. Nevertheless, within the municipalities, upon the petition of those entitled to instruction common schools shall be established of their faith or ethical system, in so far as this does not interfere with a system of school administration within the meaning of Paragraph 1. The wishes of those entitled to instruction shall be considered as much as possible. Details will be regulated by State laws in accordance with principles to be prescribed by a national law. To facilitate the attendance of those in poor circumstances at the secondary and higher schools, public assistance shall be provided by the Commonwealth, States, and municipalities, particularly, assistance to the parents of children regarded as qualified for training in the secondary and higher schools, until the completion of the training. ARTICLE 147 Private schools, as a substitute for the public schools, require the approval of the state and are subject to the laws of the States. Approval shall be granted if the private schools do not fall below the public schools in their educational aims and equipment as well as in the scientific training of their teachers, and if no separation of the pupils according to the wealth of their parents is fostered. Approval shall be withheld if the economic and legal status of the teachers is not sufficiently assured.