[Does the mind drift where it wants? Requirements for medical discoveries]

In medical discoveries, two elements may be distinguished: (1) the state of science and the available methods and tools of research at a given moment, and (2) the personal and original intellectual achievement. The relative importance of these two factors is discussed in the light of historical examples. It is apparently rare that a discovery results more or less automatically from a given state of science and research (as in the case of insulin). Nearly always the personality of the research worker turns out to be the determinant factor. Essential traits of this personality are an independent mind capable of liberating itself from dogmatic tenets universally accepted by the scientific community; the capacity and courage to look at things from a new angle; powers of combination, intuition and imagination; feu sacré and perseverance--in short, intellectual as well as moral qualities. The personality of a great scientific discoverer, furthermore, integrates the spirit of his epoch into his individuality. About half the research workers considered here were aged below 35 at the time of their discoveries. The author therefore hopes that our universities will, in the future, provide opportunities for young research workers as well as for somewhat older individualists.