Originally published in 1972 Medieval Logic and Metaphysics shows how formal logic can be used in the clarification of philosophical problems. An elementary exposition of Le?niewski’s Onotology an important system of contemporary logic is followed by studies of central philosophical themes such as Negation and Non-being Essence and Existence Meaning and Reference Part and Whole. Philosophers and theologians discussed include St Anselm St Thomas Aquinas Abelard Ockham Scotus Hume and Russell.