This book describes in two volumes the emergence and further development of the concept of molecule in the sciences and so against the background of Epicurus' neoatomism as voiced by Lucretius. 'Sciences' is here taken in the broad sense, that is: to comprise not only the exact sciences and the life sciences, but also mathematics and (natural) philosophy.

The first volume assesses, in three chapters, the period up until 1800. It next gives, in separate chapters, the vicissitudes of the molecular theory in physics and chemistry, respectively, during the 19th century. As it happened, the molecular theory came up in the Netherlands. It was invented by the natural philosopher and medicinae doctor Isaac Beeckman (1588-1637). Beeckman, a close friend of a still youthful Descartes, proposed a synthesis of Lucretius' atomic theory and Galen's medical doctrine. He developed a discrete picture of the world, in which the molecular theory featured prominently, together with a taylor-made mathematics. At the end of the 18th century the molecular theory had grown into molecularism, a real Theory of Everything. Indeed, both 19th century's physics and chemistry appear to be essentially molecular sciences.

The second volume addresses in the first chapters the development of biology and medicine and of crystallography and mineralogy. In this period biology lived its emancipation as a life science sui generis, while crystallography branched off from mineralogy. A separate chapter deals with the rise of a uniform system of units, the so-called Système international des unités, with particular attention for the molecular aspects. Up until 1925-1940 the development of the molecular theory in the different domains is analyzed in detail. For the later period the course of events is only sketched in using twelve relevant Nobel Prizes (Physics, Chemistry, and Physiology or Medicine) as beacons. The last chapter, then, concerns an epilog in which the book's theme is reconsidered from a systematic point of view on the basis of the principal new insights. The second volume concludes with a bibliography and indexes of names and subjects.

The main tenet of the book as a whole is that a new picture of the world has emerged, a picture that, in the spirit of Galileo and Huygens, was called after the House of Orange.

In more contemporary terms, acknowledging the main tenet of this book is like using appropriately Frits Zernike's phase-contrast microscope: in much the same way that that microscope enables mankind to follow in vivo the most fundamental of life's processes, the new picture of the world reveals -- step by step -- the true mechanics of several revolutionary turning points in the sciences.