Sources of the Self: The Making of the Modern Identity (Harvard University Press, 1989) is Taylor's most systematic work — a 600-page historical and philosophical reconstruction of how the modern Western self came to be organized around three great constellations of moral sources: the ideal of inwardness and self-responsible reason descending from Augustine through Descartes and Locke; the affirmation of ordinary life as a site of moral seriousness descending from the Reformation through the scientific revolution; and the expressivist turn descending from Rousseau and the Romantics that made self-expression the highest form of authenticity. The book's argument is that modern identity is richer than either its critics or its defenders acknowledge, and that its moral resources have been obscured by the narrowing of contemporary moral vocabulary to the languages of rights, procedural justice, and utilitarian calculation.
The book opens with a methodological argument: human beings are self-interpreting animals, and the frameworks within which they interpret themselves are not optional accessories to their identities but constitutive of them. One cannot describe the modern self without describing the moral sources — the frameworks of significance — that make modern identity intelligible to itself. This methodological commitment distinguishes Taylor's project from both reductive naturalism, which treats the self as a psychological mechanism, and postmodern deconstruction, which treats the self as a discursive construction without moral depth.
The historical reconstruction is the book's central achievement. Taylor traces how the inward turn associated with Augustine was transformed by Descartes into a conception of reason as self-responsible and disengaged, and how this conception was combined with the Reformation's affirmation of ordinary vocation to produce the distinctive modern emphasis on work, family, and everyday life as sites of moral significance. He then traces how the expressivist turn of the late eighteenth century transformed this framework by adding the Romantic insistence that each person has an original way of being human that must be discovered and expressed.
The book's relevance to AI is multi-layered. The achievement society that Han diagnoses is the late phase of the expressivist turn, in which self-expression has become so intense and so unconstrained that it collapses into self-exploitation. The immanent frame that Taylor later names in A Secular Age is already visible in Sources of the Self as the condition within which the moral sources of modernity operate when their transcendent dimensions have been eclipsed. And the book's central methodological claim — that human beings are self-interpreting animals constituted by the frameworks they inhabit — provides the philosophical foundation for Taylor's later insistence that computational models of mind miss what is most essential about human intelligence.
The book's argument for articulation as a method of moral inquiry is also central. Taylor does not merely describe modern identity from outside; he articulates it from within, making explicit the moral sources that moderns carry but often fail to recognize. This method of articulation is what Taylor argues is required for the recovery of the moral resources the culture has marginalized — a method that cannot be performed by any system that lacks the biographical situation required for genuine articulation.
Sources of the Self was published by Harvard University Press in 1989, emerging from nearly two decades of work that included Taylor's 1975 Hegel, his 1985 two-volume Philosophical Papers, and extensive teaching and lecturing on the history of moral philosophy.
The book won the Queen's Prize and established Taylor as one of the most important living philosophers in the Anglo-American tradition. It has since become a standard reference in debates about moral philosophy, political theory, religious studies, and the history of ideas.
Self-interpreting animals. Human beings are constituted by the frameworks within which they interpret themselves.
Three moral sources. Modern identity is grounded in inwardness, affirmation of ordinary life, and expressivist self-expression.
The narrowing of vocabulary. Contemporary moral discourse has impoverished itself by reducing ethics to rights, procedure, and calculation.
Articulation as method. Moral understanding proceeds by making explicit the frameworks of significance that shape identity from within.