Auguste Comte published the first volume of the *Cours de philosophie positive* in 1830 and the last in 1842. The work is the book that first uses the term 'sociology' and a starting point of modern philosophy of science.

Comte's central thesis is the 'law of three stages': every field of knowledge — in the individual mind as much as in the history of humanity — passes through three stages. In the theological stage, events are explained by the action of gods or spirits. In the metaphysical stage, abstract powers (essences, principles, forces) take over this explanatory role. In the positive stage, the question 'why' is abandoned, and only 'how' remains — what is sought is the observable regularity beneath the laws.

The Course also lays out a hierarchy of the sciences: mathematics at the base, with astronomy, physics, chemistry, and biology built up over it; at the top stands the newly founded 'social physics' — what Comte later called sociology. Each science uses the results of the one beneath it but establishes its own method independently. Sociology is the application of scientific method to the shared life of humanity.

After the 1840s Comte turned his ideas into a 'Religion of Humanity' — Humanity in place of God, scientific academies in place of churches; this speculation initially dampened the intellectual reception. But the methodological core — that science is cumulative knowledge built on observation and laws, and that society can also be an object of scientific inquiry — became the dominant thesis of the next century. Émile Durkheim and John Stuart Mill are, from different directions, Comte's pupils.