Moral rationalists and sentimentalists traditionally disagree on at least two counts, namely regarding the source of moral knowledge or moral judgements and regarding the source of moral motivation. I will argue that even though Leibniz's moral epistemology is very much in line with that of mainstream moral rationalists, his account of moral motivation is better characterized as sentimentalist. Just like Hume, Leibniz denies that there is a necessary connection between knowing that something is right and the motivation to act accordingly. (...) Instead, he believes that certain affections are necessary for moral motivation. On my interpretation, then, Leibniz is an externalist about judgements and motivation: he is committed to a gap between the judgement that something is morally right and the motivation to act accordingly. As a matter of fact, I will argue that there are two gaps. The first and less controversial one has to do with the fact that Leibniz reconciles his psychological egoism with ethical altruis.. (shrink)