Explanation:

- Comparative: Comte used comparative methods to analyze differences and similarities across societies. This helped him understand societal evolution and development.

- Historical: By studying historical progress, Comte believed societies could be placed in a linear progression. This aligns with his Law of Three Stages, tracing societal development from theological to metaphysical to scientific stages.

- Observation: Observation played a fundamental role in Comte's sociological studies. He emphasized empirical observation to build a science of society.

- All of the above: Answer: All of these methods were indeed used by Auguste Comte in his study of societies.