The publication of Charles Darwin’s On the Origin of Species in 1859 introduced two profound scientific ideas: Common Descent and Evolution by Natural Selection. Common Descent proposed that all life forms, from the simplest organisms to the most complex, were related and shared a single ancient ancestor. Natural Selection offered a mechanism, suggesting that variations which provided an advantage in the struggle for existence would be preserved and passed on, gradually leading to the modification of species over immense periods of time. These theories landed in the mid-19th century, a time when the natural world was generally understood to be static, having been recently created with fixed, unchanging species. The existing intellectual framework, which viewed species as immutable products of divine creation, made Darwin’s proposal of constant, undirected change inherently disruptive.
The Challenge to Human Exceptionalism
The most immediate philosophical controversy stemmed from Darwin’s suggestion that humanity was not a unique creation but simply a part of the animal kingdom. The theory of Common Descent placed Homo sapiens on the same biological tree as all other life, implying a “lowly origin” rather than a separate, divinely ordained status. For centuries, Western thought had positioned humankind as a separate entity, fundamentally distinct from the “lower orders” of nature. This anthropocentric view was undermined by the implication that humans were subject to the same undirected natural forces as every other creature.
The shock was existential, as it stripped mankind of its special separation from the competitive natural world. Darwin’s later work, The Descent of Man, made explicit the idea that human mental and moral capacities differed from those of other animals only in degree, not in kind. This continuity challenged the traditional belief in a unique, immaterial human soul and the idea that human morality was divinely implanted. The theory forced a confrontation with the idea that human existence and progress were governed by the same struggle for survival observed in nature.
Conflict with Established Religious Doctrine
Darwin’s theories directly confronted the established theological narrative of the day, particularly through the concept of “deep time.” The prevailing view in the 19th century, based on a literal reading of the Book of Genesis, adhered to a chronology that dated the world’s creation to approximately 6,000 years ago. Archbishop James Ussher’s widely accepted calculation, for instance, placed the moment of creation at the evening of October 23, 4004 B.C. Natural selection, however, required millions of years for the gradual accumulation of small variations to produce the diversity of life seen today.
The vast timescale needed for evolution directly contradicted the Young Earth chronology that had been incorporated into the margin notes of many printed Bibles. Furthermore, Darwin’s mechanism of natural selection, which operated through random variation and the impersonal elimination of the less fit, seemed to remove the need for direct divine intervention in the creation process. The idea that species were not fixed, but constantly changing, challenged the doctrine of “special creation,” where God was believed to have created each species in its present form. This clash over the Earth’s age and God’s role as a direct designer became the most famous source of public controversy.
Scientific Gaps in the Original Theory
Beyond the philosophical and religious objections, Darwin’s initial theory faced legitimate scientific critiques stemming from the limitations of knowledge in the mid-19th century. One of the “gravest objection[s]” Darwin himself acknowledged was the incomplete fossil record. Critics pointed out the scarcity of intermediate or “transitional” forms that should have been plentiful if species evolved gradually over time. Darwin was forced to appeal to the “extreme imperfection of the geological record,” arguing that the rarity of fossilization and the limited scope of current discoveries explained the missing links.
A second scientific weakness was the lack of a known mechanism for inheritance. The prevailing scientific theory of the time was “blending inheritance,” which suggested that the traits of offspring were a simple average of the parents’ traits. Critics, such as engineer Fleeming Jenkin, correctly argued that blending would rapidly eliminate any new, beneficial variation within a few generations, making natural selection unworkable. Darwin attempted to address this with his own flawed hypothesis of “Pangenesis,” proposing that particles called “gemmules” were shed from all parts of the body and aggregated in the sex organs. This mechanism was incorrect and failed to solve the fundamental problem that later required the rediscovery of Gregor Mendel’s work on particulate inheritance.
The Implications for Social Order
The controversy extended beyond biology when Darwin’s ideas were quickly misapplied to human society, giving rise to the ideology known as “Social Darwinism.” This sociological theory, championed by thinkers like Herbert Spencer, co-opted the phrase “survival of the fittest” to justify social and economic inequality. Proponents argued that the ruthless competition observed in nature should be allowed to operate freely in human affairs, especially in the economic sphere. American industrialists like Andrew Carnegie used this framework to rationalize aggressive business practices, viewing monopolistic ventures as the natural triumph of the “fittest” companies and individuals.
Social Darwinism was used to oppose any form of government intervention or welfare programs aimed at assisting the less fortunate, on the grounds that such aid interfered with the natural purging of the “unfit” elements of society. At a global level, the ideology provided a pseudo-scientific rationale for imperialism and colonialism, suggesting that the subjugation of “weaker” nations and races by “stronger” ones was an inevitable part of evolutionary progress. The concept was controversial because it served as a powerful justification for racial hierarchies and the immense class stratification of the Industrial Age.