Ideas about the diversity of matter in terms of elements and compound substances and their transformations have been pivotal to any scientific or prescientific approach to nature. From ancient natural philosophy and alchemy to modern nineteenth-century chemistry, these ideas were made the basis of philosophical systems and became the target of critical reflection. After a temporary interruption when modern philosophy of science focused on mathematical physics, philosophy of chemistry emerged anew in the 1980s and has become a flourishing field in which philosophers, chemists, and historians of chemistry are engaged. While many of the old philosophical issues have been rediscovered and discussed, new issues have also appeared as a result of shifts of general philosophical focus, alliances with historians and sociologists of science, the development of chemistry, and changes in its role in society.

Ontological Issues

The objects of chemistry are subject to many...