If we watch ourselves honestly we shall often find that we have begun to argue against a new idea even before it has been completely stated.

The air of caricature never fails to show itself in the products of reason applied relentlessly and without correction. The observation of clinical facts would seem to be a pursuit of the physician as harmless as it is indispensable. [But] it seemed irresistibly rational to certain minds that diseases should be as fully classifiable as are beetles and butterflies. This doctrine ... bore perhaps its richest fruit in the hands of Boissier de Sauvauges. In his Nosologia Methodica published in 1768 ... this Linnaeus of the bedside grouped diseases into ten classes, 295 genera, and 2400 species.

The mind likes a strange idea as little as the body likes a strange protein and resists it with similar energy. It would not perhaps be too fanciful to say that a new idea is the most quickly acting antigen known to science.

If mankind is to profit freely from the small and sporadic crop of the heroically gifted it produces, it will have to cultivate the delicate art of handling ideas. Psychology is now able to tell us with reasonable assurance that the most influential obstacle to freedom of thought and to new ideas is fear; and fear which can with inimitable art disguise itself as caution, or sanity, or reasoned skepticism, or on occasion even as courage.

If we watch ourselves honestly we shall often find that we have begun to argue against a new idea even before it has been completely stated.

The second thing to be striven for is intuition. This sounds an impossibility, for who can control that small quiet monitor? But intuition is only interference from experience stored and not actively recalled.

The fundamental activity of medical science is to determine the ultimate causation of disease.