Adam Smith, Hugo Grotius, and International Law

Adam Smith concluded The Theory of Moral Sentiments with a paean on Hugo Grotius (1583-1645), the Dutch jurist, statesman and scholar: 

Smith first got acquainted with the ideas of Grotius, and those of Samuel Pufendorf, the other greatly admired contemporary international jurist, in the lectures of his teacher Francis Hutcheson (1694-1746), who in turn was influenced by Gershom Carmichael (1672-1729), one of the first Scottish professors to teach on Grotius and Pufendorf in his classes at Glasgow University. From the 1690s onwards, natural law theories were an important part of the moral philosophy classes in Scotland, and Grotius’ idea of a secular form of natural law figured prominently. This exposure was fostered by the habit of Scottish law students (especially between 1680 and 1730) to complement their studies in the Netherlands, particularly at Leiden and Groningen. 

Grotius was a moral philosopher, theological and political scholar, covering far more fields than international law alone. Consequently, Smith referred to several of Grotius’ ideas, for example about the transfer of property, agreements, or the role and function of punishment. He even agreed with Grotius that there was no principal objection against voluntary divorce or polygamy, when these practices were allowed by the laws of the country. He did list a number of practical concerns regarding the latter though. Perhaps most importantly, Smith embraced Grotius’ idea that justice was a negative virtue, which was about what not to do, as opposed to other virtues which demanded active guidance and action by the state, and other authorities. 

However, in this contribution the focus is on Smith’s praise for Grotius’ writings on the laws of nations, or international law as we call it nowadays. Smith referred to De Jure Belli Ac Pacis (On the Law of War and Peace, 1625) as: 

Important to note is that Smith’s views on the laws of nations should be seen in the context of his general view of international politics, which he regarded as anarchic in nature, meaning that there was no overarching source of authority which disciplined the states. Also, Smith and Grotius were no pacifists. Indeed, as Tuck writes in the introduction to The Rights of War and Peace, Grotius was ‘in fact more of an apologist for aggression and violence’. Smith’s ideas were in line on this point, although, as opposed to Thomas Hobbes in Leviathan (1651), he did see possibilities for fostering international order. The laws of nations could play a role in this.  

In Lectures of Jurisprudence Smith defined the laws of nations as ’the different regulations that subsist betwixt different independent states, with respect both to the mutual intercourse betwixt them in time of peace and what privileges may be granted to them, and to the effects of the success in war and what is permitted as lawful in the time that war is waged betwixt different nations’. Smith recognized this could never be hard law. First, international law was loosely and inexactly formulated, and executed. There were hardly any rules that were agreed upon by all countries, or observed by all. Second, the existing laws of nations often failed to protect the most obvious rule of justice, namely that only the participants in a conflict received punishment. In war the innocent were often victim, while the guilty stayed out of view, which was actually in full compliance with the laws of nations. Therefore, Smith contended that in international affairs, law was often ‘no more than mere pretension and profession’. Truth and fairness were often disregarded, while treaties routinely violated, without punishment. Third, as a consequence, the binding force of international law was minimal. At best it had some limiting influence on states’ behavior in world politics, but obligations were hard to enforce, which inevitably led to looser legal and ethical norms. 

Still, Smith maintained that sovereigns had a duty to adhere to the laws of nations. In particular to the principles of just war, because they could help to limit injurious behavior towards (innocent) others. He followed Grotius’ argument that war needed the same proper foundation as a law suit before a court. The list of justified reasons for starting a war was rather long. For example, it included the violation of property rights, the case when a state failed to repay its debts, when a foreign state imprisoned a state’s citizens, the violation of a treaty, and retaliation in case of conspiracy, or foreign invasion. In addition, and in contrast to Hutcheson, Smith endorsed rules of conduct when waging a war, warning that it is was unjust to punish the whole population when only their rulers were responsible for the start of hostilities. The population should be treated humanely as should prisoners of war.  He also disagreed with Grotius on one point. The Dutchman had called ambassadors ‘spies in residence’, but Smith argued that without diplomats international trade and other dealings were impossible. 

To sum up, Adam Smith had a sophisticated view on the role of the law of nations in fostering international order. It was certainly not a panacea against all evils, and it would be unable to bring peace. Yet the law of nations still had merit. It served as guide for the behavior of leaders of state, stating the basic rules of international conduct, it provided the rules for just war and even when they did not comply, as was often the case, the laws of nations were still useful as a moral yardstick in the anarchical international society of states.    

More from this author:
Adam Smith and International Relations
Human Nature as the Foundation of Adam Smith’s International Theory
Adam Smith and Military Intervention) 

Sources: 

Marco Barducci (2021), ‘Grotius and the Enlightenment’, in Randall Lesaffer and Janne E. Nijman (eds.), The Cambridge Companion to Hugo Grotius, Cambridge: Cambridge University Press, pp. 559-577. 

Hugo Grotius (2005), The Rights of War and Peace, edited and with an introduction by Richard Tuck, Indianapolis: Liberty Fund. 

Ian Simpson Ross (2010), The Life of Adam Smith, second edition, Oxford: Oxford University Press. 

Adam Smith (1982), Lectures on Jurisprudence, Indianapolis: Liberty Fund. 

Adam Smith (1984) The Theory of Moral Sentiments, Indianapolis: Liberty Fund. 

Edwin van de Haar (2013), ‘Adam Smith on Empire and International Relations’, in Christopher Berry, Maria Pia Paganelli and Craig Smith (eds.), The Oxford Handbook of Adam Smith, Oxford: Oxford University Press, pp. 417-439. 

Edwin van de Haar (2024), ‘Human Nature as the Foundation of Adam Smith’s International Theory’, in Benjamin Bourcier and Mikko Jakonen (eds.), British Modern International Thought in the Making. Politics and Economy from Hobbes to Bentham. Basingstoke: Palgrave Macmillan, pp. 119-139.