The Theological Roots of Speciesism
Centuries before industrial slaughterhouses and mechanized research laboratories became everyday fixtures, the moral blueprint for animal exploitation was carved into Western religious philosophy. We often treat modern animal agriculture as a simple byproduct of aggressive capitalism or modern technology. Yet the intellectual machinery that justifies turning living flesh into consumable product has much deeper roots. To understand why our culture treats sentient nonhuman lives as expendable resources, we have to look back across thousands of years of theological argument.
The foundational texts of the Western tradition established a sharp divide between humans and all other forms of life. In the opening chapters of Genesis, the creation narrative grants humanity a unique status. Humans alone are fashioned in the divine image, and they receive an explicit decree to hold dominion over every beast, bird, and fish. While the initial paradise of Eden hints at an original plant-based diet, the aftermath of the Great Flood seals human supremacy in blood. God tells Noah that the fear and dread of humanity will fall upon every living thing, delivering all beasts into human hands as food. That ancient narrative etched a lasting assumption into Western culture. The world existed for humanity, and animals were placed here for human use.
This biblical mandate found a powerful ally when early church scholars encountered classical Greek philosophy. Aristotle viewed nature as an absolute ladder of purpose. In his philosophical framework, the less rational existed solely to serve the needs of the more rational. Slaves, deemed deficient in intellect, were categorized as living tools and articles of property. Extending that logic to the animal kingdom required little effort. Plants existed for animals, and brute beasts existed for mankind. When Christian thinkers later synthesized Greek philosophy with biblical scripture, this hierarchical worldview hardened into dogma.
The rise of Christianity brought profound humanitarian reforms to the Roman world, yet those reforms stopped abruptly at the boundary of our species. The church campaigned fiercely against the bloody spectacles of the Colosseum where gladiators fought to the death, declaring every individual human life sacred because of its immortal soul. At the same time, the church watched thousands of wild animals slaughtered in the very same arenas without raising a moral objection. In the New Testament, Saint Paul dismissed the idea that divine law cared for working oxen, insisting that biblical protections existed solely for human benefit. Saint Augustine took the argument further by referencing the gospel story of the swine, asserting that humans share no common rights with nonhuman beasts. Compassion became strictly bounded by biological lineage.
In the thirteenth century, Saint Thomas Aquinas formalized these ideas into an intellectual fortress that defined orthodox Catholic moral theology for centuries. Aquinas argued that there could be no direct moral duties toward animals. Sins could be committed against God, against oneself, or against human neighbors, leaving no moral room for nonhuman suffering. When asked why the scriptures occasionally discouraged cruelty toward beasts, Aquinas offered a strictly human-centered explanation. He claimed that mistreating animals was wrong only because it might habituate a person toward cruelty against other humans. The suffering of the animal itself carried no moral weight in the divine ledger.
By the seventeenth century, this theological heritage merged with the dawn of early modern science in the philosophy of René Descartes. Descartes sought to understand the physical world through the mechanics of gears, pulleys, and clocks. Everything material operated as a deterministic machine. To preserve human free will and immortality, Descartes claimed that humans alone possess an immaterial, God-given soul capable of thought and consciousness. Nonhuman animals, lacking an immortal soul, were reduced to mere biological clocks. Their yelps and cries under the vivisector’s knife were dismissed as nothing more than the rattling of mechanical springs.
This Cartesian doctrine provided researchers and institutions with absolute moral license to dissect, burn, and abuse living creatures without guilt. Though few today openly describe dogs or farm animals as unconscious machines, the underlying ethical assumption remains virtually unchanged. We have inherited centuries of theological rationalizations that treat nonhuman interests as entirely secondary to human convenience. Overcoming speciesism requires dismantling these ancient myths and recognizing that the capacity to suffer, rather than the possession of an immortal soul or abstract reason, marks the true boundary of our moral obligations.
BIBLIOGRAPHIC INFORMATION
- Title: Animal Liberation: A New Ethics for Our Treatment of Animals
- Subtitle: None (Historically subtitled: The Definitive Classic of the Animal Movement or A New Ethics for Our Treatment of Animals)
- Author: Peter Singer
- Publisher: Ecco (An Imprint of HarperCollins Publishers)
- Publication Year: 2002 (First Ecco paperback edition; original publication 1975; major revision 1990)
- Edition: 2002 Revised Edition (including the 2002, 1990, and 1975 prefaces)
- ISBN: 0-06-001157-2 (pbk.) / 0-380-71333-0
- Historical Period Covered: Ancient times (Genesis, classical Greece) to 2002, focusing extensively on the rise of intensive factory farming and laboratory experimentation from the mid-20th century to the early 2000s.
- Main Subject Areas: Applied Ethics, Animal Welfare, Philosophy of Animal Rights, History of Speciesism, Environmental Ethics, Vegetarianism/Veganism, Sociology of Social Movements.
(Ch. 5, pp. 185-197)