This book on Philosophy of Science is an attempt to introduce the topic to the students of Indian Universities. Part I of this book covers the syllabus prescribed by the University Grants Commission (U.G.C.) for the subject Philosophy of Science for M.A. students (Chapter I to Chapter V). Part II of this book provides some basic understanding on Philosophy of Mathematics, structure of the universe, Scientific Explanation and Science and Humanity (Chapter VI to Chapter IX). Most of the books on Philosophy of science focus on Karl Popper's 'falsification theory' and Thomas Kuhn's 'paradigm shift'. But Philosophy of Science is not just a 'talk' on Science; it must include the knowledge of the contents of basic sciences such as Mathematics, Physics, Chemistry and Biology. The more one knows the 'facts' of science, the wider is the scope for philosophising science. There are journals on philosophy of science published in England and America.