This book traces the development of formal logic from its origins in ancient Greece to the present day. The authors first discuss the work of logicians from Aristotle to Frege, showing how they were influenced by the philosophical or mathematical ideas of their time. They then examine developments in the present century.

Originally published in 1967. This is an examination of warrant statements – statements which indicated something about the grounds on behalf of some further judgement, choice or action. The first part of the study is concerned with the role of warrant statements in theoretical discourse; while the second part concerns their role in practical discourse. Also examined are necessity, probability, knowing, seeing and the complex of terms which allow us to introduce an argumentative structure into discourse.

This book traces the development of formal logic from its origins inancient Greece to the present day. The authors first discuss the work oflogicians from Aristotle to Frege, showing how they were influenced by thephilosophical or mathematical ideas of their time. They then examinedevelopments in the present century.

Modal propositional logic; Modal predicate logic; A survey of modal logic.