Paulo Freire, the Brazilian educator, who died on May 2 aged 75, was one of the most influential philosophers of his generation. Born into a middle-class Catholic family in Recife, Freire suffered from poverty in the years of the Great Depression, particularly after his father’s early death.

Under the influence of his mother, Freire became active in church movements. However, after reading Marx and radical Catholic thinkers, he became critical of charitable work that did things “for people” but which never involved working “with the people”.

Through the Fifties, Freire lived and worked in the marginal areas of Recife. Increasingly he came to focus on adult literacy, because it seemed “unjust that men and women were unable to read and write”. However, he also recognised illiteracy as a concrete expression of social injustice. Therefore, teaching literacy in the traditional way, using rote methods and focusing on the alphabet, was not enough. He believed literacy for adults needed to be linked to a wider process in which “learning to read the word” was related to “learning to read the world”.

This idea was central to Freire’s approach to literacy, which he developed in Recife before becoming a professor of education and then co-ordinator of a national literacy programme. After a military coup in 1964 he was labelled a subversive, imprisoned, then exiled.

While in exile, Freire wrote extensively, but he also became involved in practical work in Chile, Guinea Bissau, Nicaragua, Mozambique and many other countries before returning to Brazil in the 1980s.

Freire’s definitive work, Pedagogy of the Oppressed (published in English in 1972) was followed by 25 other books. His new “pedagogy” took its starting point from a recognition that the peasants were capable “subjects”, not passive objects. He argued that traditional education was flawed because it treated knowledge as “a gift bestowed by those who consider themselves knowledgeable upon those whom they consider to know nothing”. Freire called this “banking education” or “education for domestication” and condemned it for reinforcing the unjust structure of society. For Freire, “no education is neutral”. The educator’s role is necessarily political and should be to liberate, not domesticate.

Through the “pedagogy of the oppressed”, students would learn to perceive social, political and economic contradictions, develop a critical consciousness and start taking action to transform the world.

Freire translated his theoretical analysis into a practical methodology. The key step was to enable people to reflect on their lives. To achieve this, Freire developed “codifications” - pictures or photographs which capture essential contradictions in the local environment. Through dialogue, participants “decode” these, slowly confronting their reality. The pictures are then related to resonant “generative words” which are used to introduce reading and writing.

The radical process of “conscientisation” and social change advocated by Freire inspired a whole generation of literacy workers worldwide. To this day, most governmental adult literacy programmes in the Third World claim to be using his “psycho-social” approach, but in most cases it is distorted, as the commitment to radical change is lacking.

There are, however, practitioners across the world committed to Freire’s theory and who are constantly innovating with his ideas. Inspired by Freire, my own organisation has developed the Reflect approach, which has spread to 30 countries. In Freire’s own country, the powerful Landless Peasant Movement has taken up his methods.

Even in the UK, many initiatives are indebted to Freire, not least the Adult Learning Project in Edinburgh. Freire’s popularity here was underlined by his last visit to the UK when a huge crowd turned out at the Institute of Education in London in October 1993.

Freire touched many lives. Beneath the complexity of his theory lay a simple but never simplistic vision.

He leaves a legacy of commitment, love and hope for oppressed people everywhere.

David Archer is head of international education, Actionaid.