About

Collis Tahzib is an Associate Professor of Philosophy at the University of Southern California. His research focuses on contemporary theories of liberalism, with particular interest in the central principles of liberal political morality such as the harm principle, the principle of state neutrality, and the public justification principle. He has authored the book 'A Perfectionist Theory of Justice,' published by Oxford University Press in 2022, which explores these themes. Tahzib is also a Co-Editor of the Pacific Philosophical Quarterly, alongside Gabriel Uzquiano. Prior to his current position, he was a Junior Research Fellow in Philosophy at Merton College, Oxford University from 2019 to 2021. His academic background includes a DPhil in Philosophy from St John's College, Oxford, a BPhil in Philosophy from The Queen's College, Oxford, and an undergraduate degree in Philosophy, Politics, and Economics from Lincoln College, Oxford.

Research topics

• Political Science
• Sociology
• Law
• Law and economics
• Philosophy
• Psychology
• Computer Science
• Epistemology
• Social psychology
• Environmental ethics
• Aesthetics
• Economics

Selected publications

• Whose public reason? Which reasonableness?

  Philosophy and Phenomenological Research · 2025-02-11 · 1 citations

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  Abstract Rawlsian public reason liberalism holds that laws must be justified in terms of reasons that all reasonable citizens can accept. But who counts as a “reasonable” citizen? Rawlsians typically answer that reasonableness is conditional on acceptance of liberal values. But they do not typically defend this answer by explaining why the Rawlsian definition is superior to alternative possible definitions of reasonableness—for instance, libertarian reasonableness, perfectionist reasonableness, communitarian reasonableness, and so on. Once this full range of possibilities is set out in plain view, it creates a novel challenge which I call the which‐reasonableness challenge. This is the challenge of showing that the Rawlsian definition of reasonableness is superior to all the alternatives. In this paper, I set out this challenge (Section 1) and consider potential ways to overcome it: namely, by arguing that the Rawlsian definition of reasonableness is superior to the alternatives on grounds of its free‐standingness and stability (Section 2), its implicitness in the public political culture (Section 3), its anti‐sectarianism (Section 4), its fidelity to the underlying motivations of the public reason project (Section 5), and its avoidance of triviality, ad‐hocness, shoehorning and related perils (Section 6). I argue that while these considerations narrow the range of possible definitions of reasonableness, they do not do so by enough to uniquely pick out the Rawlsian definition. Rawlsian public reason liberals thus face a pressing challenge stemming from the simple question: Whose public reason? Which reasonableness?

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• Separateness of Perspectives, Separateness of Persons, and Duties to the Self

  Political Philosophy · 2024-05-15 · 1 citations

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  Recently, Paul Schofield has developed a highly original and sophisticated case for the existence of duties to the self. The core idea is that since each of us occupies multiple perspectives from which our interests conflict, we can be said to relate to ourselves on recognizably moral and political terms. In this article, I argue that Schofield’s argument fails because it does not take seriously enough the key disanalogy between conflicting interpersonal perspectives and conflicting intrapersonal perspectives—namely, the fact of interpersonality itself. To show this, I first argue that interpersonality offers a simple explanation of the intuitive moral difference between otherwise similar actions, thus suggesting that interpersonality is morally relevant. I then consider and reject two responses: that there are alternative explanations of this moral difference and that there is no moral difference here in need of explanation. I conclude by suggesting that this argument provides independently interesting insights into the sometimes-obscure idea of the separateness of persons. 

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• <i>A Perfectionist Theory of Justice</i> : Replies to Billingham, Laborde and Quong

  Critical Review of International Social and Political Philosophy · 2024-11-03

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• :<i>Liberalism and Distributive Justice</i>

  Ethics · 2023-03-15

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• A Perfectionist Theory of Justice

  Oxford University Press eBooks · 2022 · 38 citations

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  • Sociology
  • Political Science
  • Sociology

  Abstract Many liberal political philosophers hold that the state should not impose or even promote any particular conception of the good life or human flourishing. Instead, the state should restrict itself to maintaining a fair framework of rights and opportunities within which all citizens can pursue their own ideas about the good life. Against this backdrop, this book defends a perfectionist political philosophy. Whereas previous perfectionists have argued that the promotion of flourishing ways of life is permissible or legitimate, the author casts perfectionism as a doctrine of justice. On this view, the implementation of laws and policies designed to promote sound ideals of the good life — ideals such as moral, intellectual and artistic excellence — is not merely a legitimate complement to justice but an essential constituent of justice. Over the years, liberals have criticized perfectionism on various fronts: that it relies on value judgements that are controversial within modern pluralistic societies; that it is unduly restrictive of freedom and autonomy; that it treats citizens as if they are unable to run their own lives; that it expresses the meddlesome mentality of a village busybody; that it mistakenly assumes that there are objective truths about human flourishing; and that it risks the abuse of power by incompetent, overzealous or corrupt state officials. These ideas represent some of the deepest, most vibrant and most powerful strains in liberal thought. In defending perfectionism against these charges, the author’s arguments make a novel contribution to longstanding debates about the philosophical foundations of liberalism.

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• Political Liberalism

  2022-08-23

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  Abstract This chapter outlines the main features of political liberalism and explains why it is thought to have quite strongly anti-perfectionist implications. The discussion is organized around the following argument for anti-perfectionism commonly given by political liberals: reasonable citizens disagree in their judgements about what constitutes a good life (often called ‘the fact of reasonable pluralism’); state action must be acceptable or justifiable to all reasonable citizens (often called ‘the public justification principle’); therefore, state action must not be premised on judgements about what constitutes a good life. This chapter also explores several of the rationales that political liberals have given for the public justification principle, namely equal respect, stability and the reactive attitudes.

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• Perfectionist Law and Public Policy

  2022-08-23

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  Abstract This chapter explores what the perfectionist conception of justice might imply in terms of laws and public policies. While the discussion is tentative and does not seek to make a definitive case for any particular legislative or policy programme, the author suggests that moral excellence could be promoted through laws and policies designed to support the institution of friendship; that intellectual excellence could be promoted through informative and educational public broadcasting; and that artistic excellence could be promoted through the operation of publicly funded arts institutions and agencies. This chapter also addresses the concern that these laws and policies can already be justified on familiar liberal grounds such as freedom, equality and fairness, and so the perfectionist conception of justice turns out to be practically indistinguishable from leading non-perfectionist conceptions of justice such as those of Rawls and Dworkin.

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• Freedom

  2022-08-23

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  Abstract This chapter defends the perfectionist conception of justice against the objection that perfectionist laws and policies are unduly restrictive of freedom or autonomy. The author contends that, on the one hand, perfectionist justice is compatible with many of the conceptions of freedom found within contemporary political philosophy and that, on the other hand, the conceptions of freedom with which perfectionist justice is incompatible (such as libertarian conceptions of freedom as full self-ownership) are not in any case independently plausible. This chapter also address a more pragmatic variant of the freedom-based objection: namely that, however hospitable to freedom perfectionism is in theory, any attempt to implement perfectionism in practice would risk the abuse of political power and the violation of individual liberties by incompetent or corrupt state officials, and so common sense dictates taking ideals of human flourishing off the political agenda as a kind of prophylactic measure.

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• A Perfectionist Conception of Society

  2022-08-23

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  Abstract This chapter develops and defends a perfectionist conception of society as a fair striving for human flourishing between free and equal citizens. This conception of society serves as the fundamental basis of the author’s perfectionist political theory and as an alternative and competitor to Rawls’s conception of society as a fair system of social cooperation between free and equal citizens. Echoing Rawls’s method of defending his own conception of society, the author argues for the perfectionist conception of society partly on the grounds that it represents a plausible and recognizable interpretation of widely accepted basic beliefs and values implicit in the public political culture of liberal-democratic societies and partly on the grounds that it helps to organize our considered convictions, at all levels of generality, into a state of reflective equilibrium.

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• Paternalism

  2022-08-23

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  Abstract This chapter defends the perfectionist conception of justice against Jonathan Quong’s argument that perfectionist political action is paternalistic because it is premised on the belief that, when left to their own devices, citizens will fail to make sound choices about how to use their time and resources. In response, the author concedes that perfectionist political action does involve the assumption that citizens are not always disposed to make rational decisions about their own good, but denies that there is anything disrespectful about proceeding on the basis of such an assumption—especially given that, as mounting evidence from the fields of social psychology and behavioural economics suggests, this assumption is true of all human beings. To defend this position, the author develops an alternative conception of what respect for the moral status of citizens requires—a conception that requires that the state treat citizens as if they are disposed often, but not always, to make rational decisions about their own good, and thus that is compatible with some degree of paternalism.

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