In contrast to the most recent pedagogical trends, true education considers man as a whole, that is, body, soul and spirit. In this way, educating the body is a task that must be carried out in accordance with certain criteria, since ‘it is a means that can help or hinder Christian education’ . In the realm of the soul, the sensitive power, the principle of the passions, must also be educated, since it is responsible for moving the human being towards the good; this, then, must be ordered to the higher powers of the soul, intelligence and will, designated by the Apostle as spirit. When analysing the process of education in a philosophical way, we conclude that the learner is the main agent, while the teacher is the secondary one, being ‘an efficient cause, auxiliary, however, and subordinate to the main one, the student’ , in other words, the teacher exercises an ‘external ministry only, just like a doctor when he heals’ . The teacher is not the cause of the student's knowledge, but is responsible for transmitting the necessary and appropriate knowledge for the full spiritual, intellectual and moral fulfilment of the student. Hence the importance of the teacher, in mutual collaboration with the parents , in the integral formation of the student, not only in the natural sciences, through words, but also morally and supernaturally, through examples. A teacher's life of study does not end when he or she receives a certificate, but must be constant and orderly, keeping pace with the advance of human knowledge. In order to instruct Catholic educators in their work, the Congregation for Catholic Education states as a fundamental principle of Christian education the ‘initial and continuing formation of teachers’ , and adds that teachers should ‘possess the art of educating, in harmony with the progress of our times’ . In this sense, St Thomas, the Common Doctor of the Church, states that ‘the teacher must know the doctrine before teaching it to the disciples’ , and the Second Vatican Council states that teachers must be ‘equipped with knowledge, both profane and religious, proven by their titles, and possess the art of educating’ , because those who do not know are not capable of teaching. The Catholic teacher, who does not possess the authority of the magisterium on his own, but shares in the authority of the one true Master , must not therefore limit himself to teaching by word of mouth after brief preparation, but must follow in the footsteps of the Saviour, who for thirty years remained silent, but by his actions set an example, so that, as he did, we can do the same . In fact, the teaching of morals and good behaviour should not be exclusive to religious education, but should permeate every school environment, since it is proper for children to learn from the example of adults. In this regard, the instruction states that it is important, for the integral education of the student . A teacher who masters the doctrine he teaches, possesses the art of teaching, but does not live it well, presents himself as a risk to the good formation of his students. For this reason, the Magisterium declares, in union with the Holy Fathers and scholastic doctors, that it is the role of the teacher to give ‘witness to Christ, the only Teacher, both with life and with doctrine’.