Final answer:
Karl Marx collaborated with Friedrich Engels in his sociological writings, coauthoring the Communist Manifesto in 1848, which is pivotal in socialist thought and lays the foundation for Marxist sociology.
Step-by-step explanation:
Karl Marx collaborated with Friedrich Engels in his sociological writings. One of the most significant outcomes of their collaboration was the Communist Manifesto, coauthored in 1848, which is considered one of the most influential political documents in the history of socialist thought. This work did not only discuss political ideology, but also offered a social analysis of class struggles that exist within societies, tracing them from ancient forms of servitude and feudalism to the then-modern capitalist society. Marx and Engels theorized the progress of human society through the resolution of these class conflicts, leading towards a communist state.
Friedrich Engels, an industrialist himself, brought his own experiences and perspectives to the collaboration, enriching Marx's theories with practical insights into the workings of the economy and industry at the time. Together, they set a foundation for Marxist sociology and the sociological perspective known as social conflict theory. Their work also laid the groundwork for future socialist and communist movements, which aimed at challenging capitalistic structures and ultimately transitioning society towards socialism and communism.