This book offers an introduction to the thought of Ludwig Wittgenstein (1889-1951). Wittgenstein's life in its earlier and later periods is considered in chapters that interleave the reviews of the philosophy of language set out in Tractatus Logico-Philosophicus (1921) and Philosophical Investigations (1953). Later chapters discuss Wittgenstein's approach to philosophy and to thinking about religion and ethics. Along the way key ideas on philosophy, and relevant lines of argument that contribute to Wittgenstein's intellectual development are explained. In considering Wittgenstein's thought, the ideas of Bertrand Russell, G E Moore and A N Whitehead, amongst others, are taken into account, and prior to the review of Wittgenstein's approach to ethics the relevant background to ethical thought is discussed.