Final answer:
Karl Marx, with Friedrich Engels, popularized modern socialism and disseminated their ideas through works like The Communist Manifesto. They advocated for a transition to socialism following the overthrow of capitalist systems by the working class. Their theory, known as scientific socialism, differed from the earlier utopian socialism and influenced social conflict theory.
Step-by-step explanation:
Karl Marx is widely considered the thinker who popularized modern socialism. Along with his collaborator Friedrich Engels, Marx developed a theory of socialism that later became known as scientific socialism, making use of a scientific analytical process to interpret history as a series of class struggles. This analysis is famously presented in their collaborative work, The Communist Manifesto, published in 1848.
While Marx and Engels did not believe in setting up small utopian communities, they did advocate for a socialism that would follow after the proletariat, or working class, rebelled against capitalist owners to seize the means of production. They viewed industrial capitalism as a necessary phase that would enhance production levels to the extent that society could transition to a socialist state, and, eventually, a communist one. Their views form the cornerstone of the social conflict theory in sociology.
Contrasting the views of Marx and Engels, Louis Blanc represented state socialism and believed that social reform should come from the government. Pierre-Joseph Proudhon contributed to the concept of scientific socialism, and early thinkers like Max Weber provided critical analysis of socialism, recognizing its rational elements while cautioning against potential downsides.
The evolution from earlier optimistic forms of socialism to the analytical and revolutionary Marxism marked a significant shift in the 19th century. Despite the widespread adoption of socialist ideas and the motivating force they provided for labor organization, the reality of socialist and communist states diverged from the theory, often failing to achieve the envisioned economic or political equality.