Introduction
David Hume (1711-1776) has been characterised as one of the most influential philosophers of the modern era. His writings, although most influential in philosophy, have also been applied to jurisprudence. This essay will apply some of Hume’s philosophical ideas to the doctrine of parliamentary sovereignty both in its orthodox and modern form. The focus will be on three Humean themes which will, in turn, be applied to parliamentary sovereignty: Hume’s fork, Hume’s law, and Hume’s theory of justice and his view on definitions. This essay will begin by outlining both the orthodox and the modern views of parliamentary sovereignty. It will then ask whether the concept of parliamentary sovereignty is empirically verifiable or whether it is a tautology. Once that has been established, the essay will move on to show that the concept of constitutional statutes, particularly with reference to the Human Rights Act 1998, fall into the fallacy highlighted in Hume’s law. The natural conclusion from this is that parliamentary sovereignty should remain under the orthodox view. Then, the essay will establish whether parliamentary sovereignty or the legal supremacy of Parliament are defined properly and, in Hume’s terms, whether they portray a ‘just definition’.[1] Lastly, the piece will conclude with an analysis of Hume’s personal view of the doctrine and establish whether his perspective still has any merit today.
Parliamentary sovereignty
Under the orthodox view outlined by Dicey, parliamentary sovereignty is the idea that Parliament has legal omnipotence. This means that Parliament is free to ‘make or unmake any law whatever’[2] without any possibility of override by another body but itself.[3] However, in more recent literature, this definition has been rejected and replaced with the ‘legislative supremacy’[4] of Parliament. The difference is that while the first definition suggests that there are no limitations upon Parliament at all, the second acknowledges that, as Lady Hale (as she was then) noted in Jackson, ‘the constraints upon what Parliament can do are political and diplomatic rather than constitutional’.[5] In essence, the difference is in the sort of omnipotence that Parliament carries. Moreover, the fact that Parliament is unable to bind its successors counts as another significant limitation upon its omnipotence, since there is something that it cannot inherently do. Perhaps most significantly, the doctrine of implied repeal (which claims that if there is a conflict between a newer and an older statute, the newer statute repeals the older one) can disprove Dicey’s claim. In Thoburn v Sunderland City Council, Laws LJ posited the view that the doctrine of implied repeal does not apply to ‘constitutional statutes’.[6] Such statutes can only be repealed expressly– that is, by direct referencing that the newer Act will repeal the older one.
Is the concept of parliamentary sovereignty empirically true?
One of Hume’s main ideas is his view that all knowledge is divisible into two categories – this is also known as Hume’s fork. Based on this, knowledge can either be acquired a priori (knowledge which is independent of experience) or a posteriori (empirical knowledge). One prong is dedicated to ‘relations of ideas’[7] which are known a priori. Statements which fall into this category are tautological, or true by definition. For example, the statements ‘all bachelors are unmarried men’ falls into the first category. The other prong belongs to ‘matters of fact’[8] which are known a posteriori. These can only be known empirically. In other words, the truth of such statements is contingent upon the real world. For instance, one can only know if there is a red car parked outside of one’s house if, and only if, one checks.
The question arises as to whether parliamentary sovereignty falls into the former or the latter category. Hume seems to provide a guidance for establishing questions of this typology. The test is whether one needs to anchor to any empirical knowledge to establish whether parliamentary sovereignty is self-evident. In other words, from the definition of parliamentary sovereignty, does it logically follow that it must be true? The answer seems to be no, since it is logically possible that Parliament not be sovereign. As such, parliamentary sovereignty must be a ‘matter of fact’. Its truthfulness depends upon reality.
Where precisely does one look to find the empirical existence of parliamentary sovereignty? This is a question about sources, and, although the source of the doctrine has been debated extensively, it is enough that it exists in some form. Its specific species is irrelevant to its empirical location.
According to Hart, a rule of recognition identifies what is law in any given system.[9] The rule of recognition arises if law-applying officials behave in such a way which would correspond to the criteria of that rule of recognition. Therefore, the rule of recognition is: whatever the monarch-in-parliament enacts is law.[10] In other words, one of the rules of recognition[11] can be understood as being the doctrine of parliamentary sovereignty.[12]
Moreover, as per Hart, a rule of recognition must be accepted by law-applying officials,[13] by which ‘an attitude of shared acceptance’[14] towards that very rule of recognition develops. The rule of recognition establishes what counts as law in a legal system. Hart, like Hume[15] before him, was an empiricist and believed that one’s approach to law should be verifiable. And yet, the claim that Boos makes is that rules of recognition are unverifiable by nature.[16] This claim is easily rebuked by the establishment of actual acceptance by law-applying officials of that rule of recognition. Since it is evident that this is the case, it can be said that parliamentary sovereignty is a ‘matter of fact’ and exists empirically.
Hume’s law and its application to parliamentary sovereignty
Hume’s law claims that normative statements cannot be coherently derived from prescriptive statements. In other words, to derive what ought to be from what is, is a logical misstep. Hume claims that there is no valid inference to be made to go from one to the other. Although Hume intended this argument for moral claims,[17] the principle that he conceptualised can be applied universally.
Hume’s law has no application to the entirety of the principle of parliamentary sovereignty. As far as one can go is to say that if it is accepted that Parliament is sovereign, then normative questions about whether Parliament ought to be sovereign arise.
However, Hume’s law can be invoked to support Dicey’s perspective in challenging Parliament’s incapacity to enact Acts via an implied repeal, particularly when the Act being repealed is deemed a ‘constitutional statute’. According to Laws LJ[18], a constitutional statute is a statute that has as its focus fundamental rights, duties, or the functions of state institutions. More broadly, it focuses on the relationship between state and citizen.[19] Without reference to the creation of state institutions, both the ideas of fundamental rights and duties and the relationship between citizen and state are of inherently moral quality – that is, they are normative questions. Therefore, the normative statement becomes: ‘Parliament ought not to impliedly repeal Act A, because Act A is a constitutional statute and, by virtue of being a constitutional statute, it deals with fundamental rights’. On a Humean analysis, based simply on the words in the statute – which are descriptive – one ought not to derive a normative outlook on how that statute ought to be treated. Thus, according to this view, if a future Parliament would choose to repeal the Human Rights Act 1998, it would be able to do so impliedly – that is, treating any constitutional statute on an equal footing with other statutes. However, according to the precedent set by Thoburn over constitutional statutes which elevates such Acts[20], Parliament cannot take this path.
Hume acknowledges that reason is not the only causal element in one’s behaviour when he notes that ‘reason is and ought only to be the slave of the passions’.[21] The premise behind this argument is that people do not merely act on reason but are motivated by emotion. This is an empirically sound argument, since what connects a descriptive statement to a normative one is merely the emotion associated with the former. As such, Hume adopts the sentimentalist view of morality, which claims that ‘our moral distinctions depend on our experiencing sentiments or feelings’.[22] Hume should be taken to mean that claims regarding justice are also claims regarding sentiments. This can be used to explain the division between the word in a statute, and the normative rules generated by constitutional statutes. Any of the three issues defined as being contained in a constitutional statute can be said to evoke an emotion of justice as with respect to the relationship between state and citizens. Therefore, the conclusion is that there is at least one moral characteristic which explains the change of definition from Dicey’s to the modern one. The change is inherently a moral one, which, at its foundation, carries an understanding of justice, since it seems, at least prima facie, that it would be unjust to citizens to repeal constitutional statutes (the representative limitation). While (as will be explained below) Henry VIII clauses are a practical limitation, the representative limitation is a limitation underpinned by sentiments of justice.
Is any definition of parliamentary sovereignty a ‘just definition’?
According to Hume, one of the purposes of empiricism is to establish the true nature of whatever one is attempting to define. The way to establish this is to see whether a term corresponds to any idea. If the term does have an idea attached to it, then it has cognitive content– that is, the ideas have some definitive characteristics. After this has been done, one has to break the idea into its simplest ideas and trace those back to impressions. If this process fails at any time, then the idea has no cognitive content. But, when one manages to decompose this entirely, one reaches what Hume calls a ‘just definition’. This portrays the idea’s content entirely and without any gaps. Hume’s purpose behind this was to rid disciplines of metaphysical terms – terms such as ‘metaphysics’ or the ‘soul’ – which have no affinity to reality.
The idea that is annexed to the doctrine of parliamentary sovereignty is that Parliament holds the power to create laws at will and can repeal or amend existing laws without any external restrictions. This is broken down into its smaller parts, namely containing the concepts of legislative power and the absence of external limitations. These are then traced back to impressions (which are ‘all our sensations, passions and emotions, as they make their first appearance in the soul’[23]). While there is disagreement in the literature as to the exact moment that parliamentary sovereignty emerged or how it emerged, it seems that both concepts can be traced back to one historical moment in time, namely the passing of the Bill of Rights 1689.[24] This seems to yield a favourable result, namely that Dicey’s definition is still inherently accurate. However, this process misses one of Hume’s crucial steps: namely, that one should check whether the process fails at any point in time. The process does still fail, for it seems to be the case that, when one asks ‘can the idea of sovereignty be restricted as to link it to some other, simpler idea?’, the answer is surely a positive one. The concept can be linked to some simpler ideas, such as any theoretical or practical limitations upon parliamentary omnipotence. A clear example of this is Henry VIII clauses which are clauses which allow a minister to amend or repeal any provisions made in an Act of Parliament.[25] Since a minister is the one upon which power is delegated, theoretically it is no longer under the collective Parliament’s decision to amend or repeal the Act. Yet, this seems to be a misrepresentation, because Parliament could simply amend or repeal any enactments made by any minister. But, as Elliot points out, this is not a theoretical affront to parliamentary sovereignty but rather one to the ‘spirit of parliamentary sovereignty’, because Henry VIII clauses ‘amount to a practical diminution in the extent of Parliament’s legislative authority’.[26]
Therefore, based on Hume’s criteria, Dicey’s definition is not a just one, since it fails at connecting the idea of sovereignty to external limitations. Indeed, the point of Henry VIII clauses is not to complicate the definition, but simply to show that there is at least one limitation to Parliament’s supposed omnipotence. The mere existence of a limitation inherently means that Parliament cannot do all it wants. Dicey’s definition is almost accurate, but it is not qualified.
Is Hume’s view dead in our eyes?
David Hume did not have a theory on parliamentary sovereignty,[27] although he did see the House of Commons as superior to the Lords[28] and acknowledged that the Crown was subservient to Parliament.[29] Interestingly, Hume was not very invested in establishing a theory of sovereignty, but, rather, he was more preoccupied with explaining how that sovereignty ought to have been exercised.[30] According to Hume, the purpose of Parliament was to uphold the law, since he seems to have believed that the whole purpose of government was upholding justice.[31] As part of this view, Hume rejected Locke’s view of popular sovereignty, which claims that government is created and upheld by the people. Consequently, Locke contended that popular sovereignty was legitimised through a social contract. As such, it can be said that the legitimacy of such a contract draws itself only from the ‘State itself [being able] to satisfy the interests of its subjects’.[32] What, if anything, does this teach us about more recent theories of parliamentary sovereignty? The most fundamental question which arises is whether the fact that there are certain limitations upon parliamentary sovereignty means that it has become more just. For Hume, ‘public utility is the sole origin of justice, and that reflections on the beneficial consequences of this virtue are the sole foundations of its merit’.[33] As such, any empirically true system of parliamentary sovereignty can be justified only based on its usefulness to the citizens. For example, the implied repeal of the Human Rights Act 1998 would mean the effective removal of fundamental rights from the British constitution. The natural conclusion from this seems to be that the mechanisms of parliamentary sovereignty would not be justifiable in the eyes of citizens.
Conclusion
Applying David Hume’s philosophical ideas to parliamentary sovereignty challenges traditional views. While Dicey’s absolute legal omnipotence once defined it, contemporary discussions and constitutional statutes introduce limitations. The application of Hume’s fork and his law reject absolute perspectives, emphasising the empirical nature of parliamentary sovereignty. Analysing it through Hart’s rule of recognition highlights its dependence on real-world circumstances. Hume’s criteria for a ‘just definition’ applied to Dicey’s concept reveal simpler links, questioning its completeness, and showing that Dicey’s definition is not a ‘just definition’. Hume’s focus on justice and public utility prompts reconsideration, suggesting that parliamentary sovereignty, when evaluated empirically and morally, may require adaptation to align with justice and citizens’ interests as societies evolve.
[1] David Hume, An Enquiry Concerning Human Understanding (Oxford University Press 2007) 53.
[2] AV Dicey, Introduction to the Study of the Law of the Constitution (first published 1885, Macmillan 1915) 3.
[3] Although this claim is very controversial in the literature, the author will follow the assumption that Parliament cannot bind its successor(s).
[4] House of Commons European Scrutiny Committee, ‘The EU Bill and Parliamentary Sovereignty, Tenth Report, Session 2010–11, vol. I’ (HC 633).
[5] Jackson v Her Majesty’s Attorney General [2005] UKHL 56 [159].
[6] Thoburn v Sunderland City Council [2002] EWHC 195 (Admin) [63].
[7] David Hume, An Enquiry Concerning Human Understanding (Oxford University Press 2007) 18.
[8] ibid.
[9] HLA Hart, The Concept of Law (2nd ed, Oxford University Press 1994) 92, 110
[10] Richard Ekins, ‘The Relevance of the Rule of Recognition’ [2005] Australian Journal of Legal Philosophy 95.
[11] John Gardner correctly argues that Hart was mistaken in stating that legal systems have but one rule of recognition (both ultimate and lower down), since there can be conflicts among two of them.
[12] Ekins (n 10).
[13] HLA Hart, The Concept of Law (Oxford University Press 2012) 108.
[14] Eric Boos, ‘The Misapplication of the ‘Is-Ought’ Distinction and the Role of Justice in Hart’s Legal Theory’ (2003) SSRN Electronic Journal, 1 <http://dx.doi.org/10.2139/ssrn.460761> accessed 6 January 2024.
[15] AC Grayling, The History of Philosophy (Penguin 2019) 214.
[16] Boos (n 14).
[17] David Hume, A Treatise of Human Nature (Clarendon Press 1896) 319.
[18] Thoburn v. Sunderland City Council [2003] QB 151 [59], [63].
[19] Alec Samuels, ‘A Constitutional Statute?’ (2019) 40(3) Statute Law Review 300–309.
[20] See for example: Kacper Majewski, ‘ Re Allister: The end of “Constitutional Statutes”?’ (Constitutional Law Association, 21 February 2023) < https://ukconstitutionallaw.org/2023/02/21/kacper-majewski-re-allister-the-end-of-constitutional-statutes/> accessed 1 February 2024.
[21] Hume, Treatise (n 17) 217.
[22] Elizabeth Radcliffe, ‘Moral Sentimentalism and the Reasonableness of Being Good’ (2013) 67 Revue Internationale de Philosophie 9.
[23] Hume (n 17) 1.
[24] See for example: Jeffrey Goldsworthy, The Sovereignty of Parliament: History and Philosophy (Oxford University Press 1999) 159.
[25] Andrew Le Sueur, Maurice Sunkin, JEK Murkens, Public Law: Texts, Cases and Materials (5th edn, Oxford University Press 2023) 347.
[26] Mark Elliot, ‘Lord Judge on Henry VIII Powers and Parliamentary Sovereignty’ (Public Law for Everyone, 14 April 2016) < https://publiclawforeveryone.com/2016/04/14/lord-judge-on-henry-viii-powers-and-parliamentary-sovereignty/ > accessed 7 January 2024.
[27] Paul Sagar, ‘The State without Sovereignty: Authority and Obligation in Hume’s Political Philosophy’ (2016) 37(2) History of Political Thought 271–305.
[28] David Hume, Essays, Moral, Political, and Literary (Liberty Fund 1777) 43-46.
[29] ibid.
[30] Joaquin Varela Suanzes-Carpenga, ‘Sovereignty in British Legal Doctrine’ (1999) 6 Murdoch University Electronic Journal of Law < https://www5.austlii.edu.au/au/journals/MurUEJL/1999/31.html> accessed 7 January 2024.
[31] Hume, Essays (n 29) 41.
[32] Suanzes-Carpenga (n 30).
[33] David Hume, An Enquiry Concerning the Principles of Morals (The Open Court Publishing Co 1912) 15.
Marius Veiss
LLB (LSE) ’26 and Junior Notes Editor of the LSE Law Review Editorial Board 2023-24