Descartes recommended that we distrust the senses and rely on the ... use of our intellect.

It is both theoretically mistaken and morally wrong to regard others as objects of investigation rather than partners in free rational communication.

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.

We can't coherently deny, or even decline to affirm, that we are free.

It has taken me a long time to realize where I most disagree with Marx. His assessment of capitalism is far too favorable. He took its instability, inhumanity and irrationality to be signs that it was a merely transitional form, which had delivered into humanity's hands the means to a much better way of life than any that have ever existed on earth. Marx could not bring himself to believe that our species is so benighted, irrational and slavish that it would put up with such a monstrous way of life.

One rational standard of action is how well it promotes the end it seeks. Another standard is whether it aims at ends which are good. Both of these, but especially the former, depend on judgments of fact.

Since the Enlightenment, popular religion has rejected the Enlightenment path and transformed itself into a bastion of resistance against reason.