The criteria for good or sound theory are evident enough: it should be conceptually clear and rigorous, historically aware, able to yield substantive analysis and research agenda, and, where appropriate, able to engage with ethical issues. Theory is a necessary part of all human understanding, from the numbers of mathematics or divisions into colours we use in everyday life to the abstractions of Hegel, or of the sociologist Talcott Parsons.
International Relations as a field emerged after the First World War with the aim of studying the reasons for the history's first major conflict and means of avoiding it in future. It borrowed theories and ideas from other disciplines such as political science, economics, and to some extent sociology and anthropology but according to Halliday it sought most inspiration from international law when Woodrow Wilson's liberalism attempted to bind state actors into a legal relationship backed by the League of Nations and the incumbent study named "International Relations" was introduced in the academia (Aberystwyth, Oxford and London School of Economics) in Britain and contemporaneously in the American universities.
When International Relations took shape as a subject in the later 1 ...