The Riddle of the Universe at the close of the nineteenth century — Context and Discussion

Monism as a Weapon Against Dualism

The excerpts show Haeckel repeatedly framing his argument as a battle against dualism in all its forms. He attacks the Christian separation of body and soul, arguing that the doctrine of resurrection is 'just as materialistic' as the 'materialist athanatism' it claims to oppose. He then turns to Plato, whom he identifies as the 'chief creator' of the dualism that later entered Christianity. Haeckel's critique is blunt: Plato's idea that souls of tyrants become wolves is 'absolutely incompatible with the scientific truth which we owe to modern anatomy, physiology, histology, and ontogeny.' This rhetorical strategy—pitting empirical science against ancient or religious authority—runs throughout the excerpts. Notably, Haeckel does not offer a detailed refutation of Plato's arguments; instead, he dismisses them as absurd and incompatible with modern knowledge. The reader should note that Haeckel's own monism, as previewed here, is itself a metaphysical claim about the unity of matter and energy, not a purely empirical finding.

The Soul as Substance: A Monistic Redefinition

In a key passage, Haeckel addresses the concept of the soul as 'substance,' noting that many psychologists use the term in confusing ways—sometimes immaterial, sometimes concrete, sometimes a 'confused tertium quid.' He proposes instead to adhere to 'the monistic idea of substance,' which he develops in chapter XII. In this view, substance is 'the simplest element of our whole world-system,' and within it 'energy and matter are inseparably associated.' This is the core of Haeckel's monism: the soul is not a separate entity but a manifestation of this unified substance. The excerpts do not reveal how Haeckel reconciles this with evolutionary biology, but the chapter titles—'The Nature of the Soul,' 'Psychic Gradations,' 'The Embryology of the Soul'—suggest he will trace the soul's development from simpler forms. Readers should watch for how Haeckel moves from this abstract definition to concrete claims about human consciousness and immortality, which he addresses in later chapters.

The Rhetoric of Science vs. Revelation

Haeckel's preface sets the stage by describing the nineteenth century as marked by 'open contradiction' between science and traditional 'Revelation.' The excerpts bear this out: he treats Christian beliefs as myths to be debunked by 'pure reason.' For instance, he quotes Savage's remark that ecclesiastical doctrine of a future life 'has always been, and still is, materialism of the purest type,' using a religious critic to bolster his own position. Yet Haeckel's own language is not neutral; he describes Platonic morality as 'childish naïvety' and Christian sermons as 'ornate discourses.' The catalog subject 'Religion and science' is thus presented not as a dialogue but as a conflict in which science holds the winning hand. However, the excerpts are incomplete—they do not show Haeckel engaging with contemporary scientific objections to his monism, nor do they reveal how he handles the problem of consciousness. The reader should approach his claims as part of a polemical tradition, not as settled science.

Haeckel's book is best read as a period document of late-nineteenth-century scientific naturalism, where evolutionary theory was deployed to challenge religious and philosophical orthodoxies. The excerpts show a writer confident in his synthesis but prone to sweeping dismissals. Readers interested in the history of science and religion will find here a clear statement of monist principles, but should supplement it with contemporary critiques to gauge the strength of Haeckel's arguments.

The rain kept up all afternoon, and I drifted through Haeckel’s confident dissolving of soul into matter, his brisk verdicts on Plato and resurrection. By evening, that certainty felt too tidy, and I found myself missing the notion of limits—so I pulled down the Hamilton critique instead, letting its narrower, thornier questions settle the room. Know the Truth: A Critique on the Hamiltonian Theory of Limitation Including Some Strictures Upon the Theories of Rev. Henry L. Mansel and Mr. Herbert Spencer — A Closer Reading seemed to answer something Haeckel never asked. The rain never let up.