Intended for healthcare professionals

Rapid response to:

Education And Debate Complexity science

Coping with complexity: educating for capability

BMJ 2001; 323 doi: (Published 06 October 2001) Cite this as: BMJ 2001;323:799

Rapid Response:

All Non-linearity is not Chaotic

Dear Sir,

I enjoyed the paper by Paul Plsek and Trish
with its sweeping overview of the world of medical activity seen from
the perspective of complexity science, however I think the treatment of
linearity was potentially misleading.

All chaotic systems are non linear but not all non linear systems are
chaotic(2). The sensitivity to initial conditions of a system is a
of chaos rather than non-linearity. Most deterministic relationships
in medicine are non linear. For example the dose-response curve for a
drug is
non linear but,generally,the effect is not chaotic.

Yours faithfully,

Gerald Partridge M.A, M.R.C.G.P.


Holycroft Surgery,
Keighley BD21 1SA


1 Plsek P.E,Greenhalgh T. BMJ 2001;323;625-8

2 Hilborn R.C."Chaos and Nonlinear Dynamics" O.U.P. 2000

NB. Competing interest: NONE

Competing interests: No competing interests

26 October 2001
G W Partridge
General Practitioner
Holycroft Surgery, Keighley, BD21 1SA