In the study of International Relations few terms cause more confusion than sovereignty. As all the territorial participants in international life proclaim themselves to be sovereign it is a difficult term to get away from. But it also seems enormously difficult to get hold of, at least in any way which combines clarity and helpfulness. The matter is not assisted by the common suspicion that sovereignty has something to do with law, for law is widely taken to be an element to which any level-headed student of the international scene will give little time. On the other hand, sovereignty is also often supposed to have something to do with power—and that is a factor which, it is generally agreed, commands attention. However, in addition sovereignty has at least the smell, if not the clear suggestion, of absolute power—and that surely is something which is hardly applicable to any of the world's states, not even the super-states. All that can be said with confidence about them is that they are stronger than the others—but in that case what price the equality which sovereign states profess on the ground that they are all sovereign?

The history of recent efforts to establish a science of international politics may be usefully viewed as elaborate glosses on David Hume's powerful philosophical programme for resolving, reconciling or dissolving a variety of perspicuous dualities: the external and the internal, mind and body, reason and experience. Philosophers and historians of ideas still dispute the extent to which Hume succeeded but if one is to judge by the two leading ‘scientific’ research programmes1 for international politics—inductivism and naive falsificationism —these dualities are as unresolved as ever, with fatal consequences for the thesis of the unity of the sciences. For the failure to reconcile or otherwise dissolve such divisions shows that, on the Humean view, there is at least one difference between the physical (or natural) sciences. and the moral (or social) sciences: namely, that while the latter bear on the internal and external, the former are concerned primarily with the external. How much this difference matters and how the issue is avoided by the proponents of inductivism and naïve falsification is the subject matter of this paper.

The systematic critique of scientific approaches to international politics began with Stanley Hoffmann's provocative 1960 essay, climaxed with Hedley Bull's popular piece in World Politics six years later and breathed its last gasp with Oran Young's attack on Russett's International Regions and The International System in 1969, Since then, the traditionalists have chosen to ignore the behavioralists.

Scientific research, because it requires the explicit, rigorous specification of hypotheses and the equally rigorous, explicit empirical investigation of those hypotheses, facilitates and invites penetrating examination, empirical replication, and intelligent criticism. Yuen Foong Khong's (hereafter Khong) commentary on The War Trap is an able, sincere effort at exactly such examination, replication, and criticism. He has raised important questions, the response to which may help to further communication and understanding between what Khong calls the behavioralists and the traditionalists. Indeed, if Khong's essay succeeds in re-establishing serious communication and cross fertilization between the ‘traditionalists’ and the ‘behavioralists’ he will have made an important, and hopefully lasting, contribution.

In the short space allotted mes I, shall address the major issues raised by Brace Bueno de Mesquita's response to my review of The War Trap. His five most important points are as follows:

Professor Krasner's article ‘Third World vulnerabilities and global negotiations’ in the October issue of the Review (Vol. 9, no. 4) is an attempt to provide an alternative way of thinking about the North-South dialogue. The central thesis is that Third World states are concerned with power rather than wealth; that politics and not economics is the overriding determinant of their motivation in seeking changes in the international economic order, Krasner therefore urges Northern states to approach global negotiations with caution and to begin discussions only in those limited areas seen as capable of satisfying mutual economic interests. Indeed Krasner's article reads like a policy document; a paper prepared to catch the eye of the Reagan administration perhaps? Underpinning his analysis is the notion of Third World vulnerability. It is the internal and external vulnerability of these regimes, we are told, which best explains their policy positions.

Marc Williams' ‘The Third World and global reform’ raises several fundamental questions about my analysis of the Third World's quest for a New International Economic Order. His most serious criticisms are that I (1) misunderstood the relationship between politics and economics; (2) covertly endorse an orthodox liberal policy prescription for the North; and (3) mis-state the implications that can be drawn from data on the economic situation of developing countries. I will address each of these issues.