There is a lot in Adam Smith that reflects the insights of Rousseau and anticipates those of Marx.

Our procedures of deliberation are not ways of finding out independent moral truths but instead ways of "constructing" these truths, in the process of deciding what to do.

There is a very common, though also very silly, picture of Kant according to which as empirical beings we are not free at all, and we are free only as noumenal jellyfish floating about in an intelligible sea above the heavens, outside any context in which our supposedly "free" choices could have any conceivable human meaning or significance. Part of the problem here is that Kant faces up honestly to the fact that how freedom is possible is a deep philosophical problem to which there is no solution we can rationally comprehend.

Clearly no working class movement ever came about that was able to do what Marx was hoping for.

In general, those who defend capitalism are basically out of touch with reality.

As Kant says, the contribution of any common laborer would be greater than that of the greatest philosopher unless the philosopher makes some contribution to establishing the rights of humanity.

For the utilitarian, there is a fact of the matter about the good (the general happiness, or whatever conception of the good the utilitarian adopts) and about which actions or moral rules would contribute to maximizing the good. For the rational intuitionist, there are truths about which actions should be done and not done.