This is the first book to provide a student-friendly introduction to propositional and predicate calculus, which is central to the broad field of mathematical logic. The book is aimed at undergraduates with no prior experience of logic. It does assume some mathematical background, but only that which is standard in the first year of a mathematical degree, and contains pointers for students without this background making it suitable for both mathematics and computer science courses.The book concentrates on the core material and provides a solid foundation for further study. The emphasis is on statements about mathematical structures, formal proofs representing mathematical arguments, and mathematical applications of results. The final chapter is devoted to some of the applications of the compactness theorem within Model Theory. It is specifically designed for self-study and features a wealth of exercises to encourage students to help develop results and consolidate understanding.