Salesian Preventive System is the educative method developed by the Salesians upon the pedagogical experience of Saint John Bosco with poor youngsters in 19th century Turin. It is based on three pillars: reason, religion and loving-kindness. It is also opposed to what Don Bosco refers to in education as the Repressive System of Education. Even if Don Bosco appears as the main representative of this method of education and formation of the young, other characters have contributed to its previous development like Philip Neri and Francis de Sales.