He depicts two distinct systems: one, codified and written, whose characteristics are regularity and reproducibility most like Western medicine, and the other, relying on oral tradition, sometimes with hazardous implications when healers no longer respect rituals, as in Dakar, Senegal.
He emphasizes the importance of these ritual practices in the management of natural resources, talks about the effectiveness of taking medicine and the relationship between the traditional healer and his patient. He insists on the global character of these methods based on an ancestral tradition. This is why it is difficult to measure the complexity of these traditional medicines in the laboratory.
Finally, he notes that the ethnopharmacological approach makes it possible to identify this endangered naturalistic knowledge.
Numerous film excerpts illustrate his discussions.