Titan en Christiaan. Huygens in werk en leven

In three respects Christiaan Huygens (1629-1695) poses a biographical problem. Unlike contemporaries he hardly ever reflected upon what he thought he was doing; his versatility makes it hard to gain a balanced view of what he was doing; his personality seems almost absent from his writings. In the present paper I seek to get the problem in sharper focus by taking a look at CD. Andriesse's widely-read biography Titan kan niet slapen (1993). Here Huygens' personal life provides the starting-point for a primarily psychological portrait which, however, does not shed new light upon the historical placement of his scholarly work. An account (derived from my doctoral dissertation) of how unpredictably Huygens' famous 'principle' of light propagation arose from his dioptrical work is then used as one example of the way in which such a historical context may be reconstructed. What we find that way is a fairly traditional student of geometrical optics who - inadvertently it seems - made a pioneering contribution to a new kind of physical optics once he extended the mathematics of ray optics to the mechanistic nature of light. Expanding further such a historization of Huygens' optical work, we can begin to ask more pointed questions about his personality, for example, about his apparent reluctance in many a case to show himself up as the kind of innovator he really was