Marx's writings still have something to teach us about capitalism. They have little or nothing to teach us about any alternatives to it. Anyone who had read them knows that.

It is actually a nice question how far Descartes himself endorses the monological and metaphysically dualistic theory of mind associated with his name and his legacy in early modern philosophy. But Fichte does reject this tradition, by suggesting that an immaterial thinking substance is an incoherent notion, and a rational being whose rationality was not developed through communication with others is a transcendental impossibility.

Empiricist philosophy always tends to be anti-philosophy (and is often proud of it).

The species of anti-Enlightenment religion we find among evangelical protestants is far more impoverished, anti-intellectual and downright wretched.

Kant does not think that the silly commandment "universalize your maxims" is the be-all and end-all of ethics or that it provides us with some sort of general decision procedure that is supposed to tell us what to do under all circumstances.

We cannot predict the effects of our actions, especially our collective actions over generations or centuries, to use instrumental reasoning toward these big final ends to tell us what we ought to do.

My own view is that Kant's conception of the duality of the good (morality and happiness, the good of our person and the good of our state or condition) is a distinctively modern view.