His legacy
Comte saw two universal lawss at work in all sciences, the 'law of three phases' and the 'encyclopedic law'. By combining these laws, Comte developed a systematic and hierarchical classification of all sciences, including inorganic physics (astronomy, earth science and chemistry) and organic physics (biology and for the first time, physique sociale, later renamend sociologie).
This idea of a special science - not the humanities, not metaphysics - for the social was prominent in the 19th century and not unique to Comte. The ambitious - many would say grandiose - way that Comte conceived of it, however, was unique.
Comte saw this new science, sociology, as the last and greatest of all sciences, one that would include all other sciences, and which would integrate and relate their findings into a cohesive whole.
Although influential within his own lifetime and for a short while afterwards, Comte's work fell into disrepute rapidly after that. Comte coined the term "sociology", is usually regarded as the first sociologist, and his emphasis on the interconnectedness of different social elements was a forerunner of modern functionalism. Nevertheless, with few exceptions, his work is now regarded as eccentric and unscientific, and his grand vision of sociology as the queen of all the sciences never came to fruition.
See also: Positivism