ABSTRACT
This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book shows that the dispositional modality is indeed central to whole philosophy and the basis of solutions to many philosophical problems. It presents some of the issues that can be understood better by embracing the dispositional modality. The external principle contains the positive component of a cause that typically has an effect, which is what L. Glynn identified as the directedness component of the dispositional modality. The external principle says that people should accept the modality of nature to be tendential because while a cause is for a typical effect, any cause can be interfered with in a way that prevents its effect from occurring and this shows that causes do not necessitate their effects. The external principle has the implication that causes did not necessitate their effects even on the occasions where they succeeded in producing them.
