Most moral systems aim at the general good of humanity (or a subset thereof). This is certainly true of Smith's Theory of Moral Sentiments,
1759 and Comte's System of positive philosophy, which was published a century later. But it is Smith's work which is more revolutionary. If you assume the goal of morals to be the general good of humanity, then one obvious way of going about it is Comte's - namely to enforce on every human in every culture that would ever live an all-encompassing systematic way of behaving. This is quite dictatorial and also fits many of the major world religions. Comte's is an extreme form whereby a set of rules for acting is defined and against which all humans will be judged. Society will cohere around this set of rules, and rule-breakers would expect to pay a price which such a society saw fit to exact. In essence, the ought which underlies the moral system as it applies to human beings in general gets directly encoded in terms of rules for individuals. There is within it an implicit top-down homogeneous model of behaviour which identically reflects the goals at the level of Humanity. That is to say, once the starting point of "what's good for humanity" has been worked out, then the rules individual human beings ought to follow just drop straight out of the analysis.
With Smith, things are quite different. Still present is an ought model of human behaviour but in his system individual humans could behave as self-interestedly as they liked, so long as the right economic structures were in place to transform such self-interested behaviour into outcomes which could maximise good for humanity in general. What a fundamental difference this is between the model of individual behaviour (a realistic is) and the goal of maximising human happiness (ought), especially when compared to the much more simplistic Comtian one. In this one sense the intellectual development of social philosophy was stronger a century earlier - a clear counter-example to the implicit evolutionary, monotonically improving history of ideas you find within Comte
