To the Editor: Van Der Weyden has asked a provocative question about the relevance of what he calls "medicine's homage to health".1 In so doing, he pays his own homage to a world where boundaries are sharp and healing becomes reduced to a matter of applying "bioscience to matters of mind and body".

While I daresay many editors of biomedical journals would share his view, he is only highlighting an age-old tension. Indeed, Crookshank wrote in 1926 about the Ancient Greek schools of Cos and Cnidus, and of their debate about doctrines of the natural/descriptive and the conventional/academic approaches to medical knowledge.2 The Coans promoted the importance of the influence of the individual and society on the presentation of illness, and managed illness holistically with regimens oriented towards the needs of the individual, while the Cnidans oriented their practice around the distinctions between diseases, treating specific diseases with specific remedies.3

These differing approaches to illness and disease highlight the conflict between cybernetic and linear thought which has underpinned medical history ever since. It is rarely understood that the linear doctrine of biomedicine has only become dominant in the last century or so. Medicine's isolation from contemporary scientific thought explains our long delay in confronting the challenges of systems thinking — challenges that the basic and applied sciences took on in the early years of the 20th century.4

Our contemporary error is in assuming that the accumulation of data that passes for modern medical knowledge is sufficient to deal with the tasks of medicine. The disquiet expressed by Van Der Weyden is only a symptom of the continuing inability of a mechanistic view of medicine to deal with caring for patients in the real world.