Offering a new approach to scientific explanation, this book focuses initially on the explaining act itself. From that act, a "product" emerges: an explanation. To understand what that product is, as well as how it can be evaluated in the sciences, reference must be made to the concept of the explaining act. Following an account of the explaining act, its product, and the evaluation of explanations, the theory is brought to bear on these issues: Why have the standard models of scientific explanation been unsuccessful, and can there be a model of the type sought? What is causal explanation, and must explanation in the sciences be causal? What is a functional explanation? The "illocutionary" theory of explanation developed at the outset is used in discussing these issues, and contrasting philosophical viewpoints are assessed.