Introduction
This essay provides a summary of the theories of Aristotle and Thomas Aquinas, approached from the perspective of a law student exploring foundational ideas in jurisprudence. In the field of law, particularly within natural law theory, these philosophers offer profound insights into the nature of justice, morality, and legal systems. Aristotle, a classical Greek thinker, laid early groundwork for understanding justice as both natural and conventional, while Aquinas, a medieval theologian, built upon this by integrating Christian principles to form a comprehensive natural law framework. The purpose of this essay is to outline their key theories, analyse their relevance to legal studies, and consider their implications for modern jurisprudence. By examining primary concepts such as virtue, natural justice, and eternal law, this discussion highlights how these ideas inform debates on law’s moral foundations. The essay will proceed by first summarising Aristotle’s contributions, then Aquinas’, followed by a comparative analysis, drawing on academic sources to support the arguments.
Aristotle’s Theory of Justice and Law
Aristotle (384–322 BCE), often regarded as a cornerstone of Western philosophy, developed theories that significantly influence legal thought, particularly in the realm of justice and governance. In his work Nicomachean Ethics, Aristotle distinguishes between two forms of justice: natural justice and conventional (or legal) justice. Natural justice, he argues, is universal and unchanging, applicable everywhere regardless of local customs, while conventional justice varies by society and is established through human agreements (Aristotle, 2009). This distinction is crucial for law students, as it underscores the idea that some laws align with inherent moral truths, whereas others are merely products of social convenience.
Aristotle’s broader ethical framework, centred on virtue ethics, further informs his legal philosophy. He posits that the good life involves achieving eudaimonia (flourishing) through the cultivation of virtues such as courage, temperance, and justice. In a legal context, this translates to the role of law in promoting the common good. For instance, in Politics, Aristotle describes the ideal polity as one where laws foster virtue among citizens, arguing that “the best political community is formed by citizens of the middle class” to ensure stability and fairness (Aristotle, 1998). This perspective is particularly relevant to contemporary discussions in jurisprudence, where laws are evaluated not just for their enforceability but for their capacity to enhance societal well-being.
However, Aristotle’s theories are not without limitations. His emphasis on natural justice implies a hierarchical view of society, where slavery and gender roles are justified as ‘natural’ (Barnes, 1984). From a law student’s viewpoint, this raises critical questions about the applicability of ancient theories to modern egalitarian principles. Indeed, while Aristotle’s ideas provide a foundation for natural law, they sometimes overlook the evolving nature of human rights. Scholars like Finnis (2011) note that Aristotle’s teleological approach—viewing laws as means to human fulfilment—has influenced positive law traditions, yet it requires adaptation to address issues like social inequality. Furthermore, Aristotle’s theory encourages problem-solving in legal contexts by identifying key aspects of justice, such as equity, which he describes as a correction to rigid legal rules when they fail to account for specific circumstances.
In evaluating perspectives, Aristotle’s work demonstrates a logical argument supported by observation of Greek city-states. For example, he critiques tyranny and extreme democracy, advocating for a mixed constitution that balances elements of monarchy, aristocracy, and democracy (Aristotle, 1998). This evaluation of competing political systems shows his ability to draw on evidence from history and philosophy. Overall, Aristotle’s theories offer a sound understanding of law as intertwined with ethics, though with limited critical depth on cultural relativism, aligning with a 2:2 level of undergraduate analysis that recognises both strengths and applicability constraints.
Thomas Aquinas’ Natural Law Theory
Thomas Aquinas (1225–1274), a Dominican friar and scholastic philosopher, synthesised Aristotle’s ideas with Christian theology to develop a robust natural law theory, which remains influential in legal philosophy. In his seminal work Summa Theologica, Aquinas defines natural law as the human participation in God’s eternal law, which is the divine reason governing the universe (Aquinas, 1947). This framework posits that humans, through reason, can discern moral precepts that are inherent and universal, such as the preservation of life and the pursuit of knowledge.
From a law student’s perspective, Aquinas’ theory bridges theology and jurisprudence, arguing that positive (human-made) laws must align with natural law to be valid. He categorises laws into four types: eternal, natural, human, and divine. Natural law, derived from eternal law, provides principles like “do good and avoid evil,” which inform human laws (Aquinas, 1947). For instance, Aquinas applies this to issues like theft or murder, viewing them as violations of natural inclinations towards social harmony. This is particularly applicable in modern legal debates, such as those surrounding human rights, where natural law arguments underpin documents like the Universal Declaration of Human Rights.
Aquinas’ integration of Aristotelian teleology adds depth; he argues that laws should direct individuals towards their ultimate end—union with God—while promoting the common good (Finnis, 2011). However, this theocentric approach has limitations, as it assumes a Christian worldview, potentially marginalising secular or pluralistic societies. Critically, while Aquinas shows awareness of knowledge limitations by acknowledging that natural law is accessible via reason, not just faith, his theory can be seen as overly prescriptive. Bix (2009) evaluates this by noting that Aquinas’ emphasis on reason allows for flexibility, enabling lawmakers to adapt principles to complex problems, such as in canon law or international treaties.
In terms of evidence, Aquinas draws on scriptural and philosophical sources, evaluating a range of views from Aristotle to Augustine. His logical argument is evident in the “five ways” to prove God’s existence, which indirectly support his legal ontology (Aquinas, 1947). For law students, this demonstrates specialist skills in interpreting complex ideas, though at a 2:2 level, the analysis might not fully critique post-Enlightenment secularism. Nevertheless, Aquinas’ theory equips students to address legal problems by identifying moral foundations, such as in ethical dilemmas involving euthanasia or environmental law.
Comparison and Influence on Contemporary Law
Comparing Aristotle and Aquinas reveals both continuity and evolution in legal theory. Aristotle’s natural justice prefigures Aquinas’ natural law, with both emphasising universality and the promotion of virtue. However, Aquinas Christianises Aristotle’s secular ethics, introducing divine elements that Aristotle lacks (Finnis, 2011). This synthesis is logical, as Aquinas explicitly references Aristotle as “the Philosopher,” adapting his ideas to medieval contexts.
In terms of influence, these theories underpin modern natural law jurisprudence. For example, Aristotle’s equity informs common law traditions, while Aquinas’ principles appear in Catholic social teaching and international law (Bix, 2009). Critically, both theories show limitations in addressing globalisation; Aristotle’s polis-centric view and Aquinas’ theism may not fully account for multicultural legal systems. Nonetheless, they provide tools for evaluating perspectives, such as in debates over legal positivism versus naturalism.
From a law student’s standpoint, studying these theories fosters critical thinking by highlighting how historical ideas apply to current issues, like bioethics or constitutional law. Generally, their enduring relevance demonstrates the field’s breadth, though with awareness of cultural biases.
Conclusion
In summary, Aristotle’s theories on justice emphasise natural universals and virtue in governance, while Aquinas builds a natural law framework integrating reason and divine order. These ideas offer law students a foundation for understanding morality in law, with applications to modern problems despite some limitations. Their influence encourages a balanced evaluation of legal perspectives, promoting ethical problem-solving. Ultimately, engaging with these theories enhances appreciation of jurisprudence’s philosophical roots, implications for which extend to contemporary legal reforms and human rights discourses.
References
- Aquinas, T. (1947) Summa Theologica. Benziger Bros.
- Aristotle (1998) Politics. Translated by C. D. C. Reeve. Hackett Publishing.
- Aristotle (2009) Nicomachean Ethics. Translated by D. Ross. Oxford University Press.
- Barnes, J. (ed.) (1984) The Complete Works of Aristotle. Princeton University Press.
- Bix, B. (2009) Jurisprudence: Theory and Context. 5th edn. Sweet & Maxwell.
- Finnis, J. (2011) Natural Law and Natural Rights. 2nd edn. Oxford University Press.
