Part Three: Life, Mind and Matter¶
Core Argument¶
In the third part of the text, the earth is presented as a system of continuous movement and transformation, where the history of geology itself reflects the ideological and scientific struggles of its time. Early geology, rooted in observation rather than experiment, was shaped by religious dogma, particularly in France, where catastrophism—the view that Earth’s history consisted of long periods of stability punctuated by brief, violent events—reconciled empirical findings with Biblical accounts. In contrast, Lyell’s gradualism, emerging from the English reformist tradition, posited slow, continuous change without sudden leaps. Engels praised Lyell for introducing the concept of gradual transformation but criticised him for treating natural forces as constant and lacking directional development. The text argues that the opposition between gradualism and catastrophism is artificial; Hegel’s concept of the nodal line of measurement, where quantitative changes give rise to periodic qualitative leaps, provides the correct dialectical framework for understanding geological change.
This dialectic is vividly illustrated by the fate of Wegener’s theory of continental drift, rejected for sixty years in favour of isostacy. Technological advances linked to oil exploration eventually provided evidence for a dialectical process: gradual sediment build-up, destabilised by falling sea levels, leads to sudden collapse. Deep-sea drilling confirmed seafloor spreading, giving rise to plate tectonics, which negates isostacy and returns to Wegener’s theory on a higher level. The earth’s crust is composed of plates in constant motion, driven by magma creation at mid-ocean ridges and subduction elsewhere. This process is not linear but proceeds through contradictions and cataclysmic leaps, as oceans close and continents collide. The theory dialectically combines all phenomena, showing that stability is violently interrupted by revolutions on a continental scale.
The fossil of a marine animal found inland by a young Charles Darwin contradicted existing theories; an eminent geologist hoped the find was false rather than accept continental movement. Such movement, averaging 1-2 cm per year, is imperceptible to common sense but produces dramatic changes over millions of years. Rocks containing marine fossils atop the Himalayas show that the ocean floor was thrust upwards over 200 million years through contradictions: upheavals, earthquakes, breaks, and folds. Mountain chains form when an ocean is pressurised between continents, forced under one, and rocks fold; after ocean disappearance, continents collide, thickening the crust vertically. The collision of Euro-Asian and African plates created a chain from the Pyrenees to the Himalayas. Seismically active zones are plate borders. At a critical point, quantity transforms into quality: even the hardest rocks break or deform plastically, expressed in earthquakes. Rocks initially resist pressure but become channels for its release. Opposing surface forces—weathering, erosion—transport matter back to oceans, where particles consolidate into new rocks. Subterranean heat, from radioactive decay, melts rocks; partial melting produces magma that moves upwards, halted by barriers until pressure forces a violent breakthrough. These processes follow fundamental laws, occurring at plate borders. The Archaean-Proterozoic boundary marked a qualitative leap: aggregation of small plates into larger, thicker ones, with major mountain building episodes 1.8 billion and one billion years ago. Uniformitarianism does not apply to early Earth; modern plate tectonics began in the early Proterozoic.