This text is a wonderful introduction to anyone studying modality or even just interested in the subject. Melia provides a clear, easy to read overview of the subject. Although the book is fairly short, it contains a lot of very useful information. For anyone wanting to explore any of the issues in more depth, Melia includes a list of suggested further reading. One thing I should point out is that certain chapters of this book require a fairly decent grasp of logic, so if you don't have any grounding in formal logic it may be worth reading this alongside a logic text.