Etiology as a Pragmatic Concern
Epidemiological research is, almost exclusively, concerned with etiology of illness; but the concept of this remains quite generally misunderstood. To wit, according to A Dictionary of Epidemiology (2009) – a “handbook” sponsored by the International Epidemiological Association – etiology is “Literally, the science of causes, causality; in common usage, cause.” (Tautology is not, literally or otherwise, the science of unnecessary repetition; nor is morphology, literally or otherwise, the science of shape, even though an important aspect of many sciences.)
For a student in an introductory course on epidemiological research it is essential to learn, for a start, that etiology – we prefer to term it etiogenesis (in analogy with ‘pathogenesis’ for the closely related descriptive concept) – is one of the two fundamental concepts of causation in medicine. And then the need is to learn, securely, the essence of this particular genre of causation in medical thought, to learn to distinguish it from interventive causality.
Once the medical concept of etiology/etiogenesis has been correctly introduced and internalized by the students, they are ready to be introduced to the role of etiogenetic knowledge in (the practice of) community medicine – in community etiognosis, preparatory to any action (education, regulation, or service) aimed at reduction of morbidity from some particular illness(es). In this etiognosis, general/abstract knowledge about etiogenesis is brought to bear on ad-hoc facts, to arrive at this particularistic type of knowing (about the causal origin of a given rate of morbidity in the community/population being cared for).
Community etiognosis (about a morbidity rate) has its counterpart in clinical medicine, focusing on a single case of an illness – or sickness not due to illness – and thus differing in its particulars from community etiognosis. The requisite knowledge is generally considerably more detailed/specific than in community etiognosis, and hence distinctly less secure (in today’s context at least).
Clinical etiognosis is quite commonly a concern in legal contexts as well, but there it takes on a character different from what it is in clinical practice.