Schopenhauer and Compassion as the Basis of Morality

From Schopenhauer's The World as Will and Representation comes the following excerpt that privileges compassion over reason as the basis of moral life:

Let us suppose that two young men, Caius and Titus, are passionately in love each with a different girl, and that, on account of external circumstances, each is thwarted absolutely by a specially favoured rival. They have both decided to put their rivals out of the way, and are perfectly secure from all detection, even from all suspicion. When, however, each comes to make more detailed arrangements for the murder, he desists after an inward struggle. They are now to give us a sincere and clear account of the reasons for abandoning their decision. Now, that given by Caius is to be left entirely to the reader's choice. He may have been prevented through religious reasons, such as the will of God, the retribution to come, the Day of Judgment, and so on. Or he may say: "I consider that the maxim for my proceeding in this case would not have been calculated to give a universally valid rule for all possible rational beings, since I should have treated my rival only as a means and not at the same time as an end." Or he may say with Fichte: "Every human life is a means to the realisation of the moral law; hence I cannot, without being indifferent to that realisation, destroy one who is destined to contribute to it." (Incidentally, he could get over this scruple by hoping, when once in possession of his beloved, to produce soon a new instrument of the moral law.) Or he may say in accordance with Wollaston: "I considered that this action would be the expression of a false proposition." Or like Hutcheson he may say: "The moral sense whose feelings, like those of any other, are incapable of further explanation, prevailed on me not to do it." Or like Adam Smith: "I foresaw that my action would not excite any sympathy at all for me in those who witnessed it." Or in the words of Christian Wolff: "I recognised that I should thus work against my own perfections and not help that of another." Or he may use the words of Spinoza: "To man nothing is more useful than man; I was therefore unwilling to kill the man." In short, he may say what he likes.

But Titus, whose account I reserve for myself, may say: "When it came to making the arrangements, and so for the moment I had to concern myself not with my passion but with that rival, I clearly saw for the first time what would really happen to him. But I was then seized with compassion and pity; I felt sorry for him; I had not the heart to do it, and could not." Now I ask any honest and unbiased reader: Which of the two is the better man? To which of them would he prefer to entrust his own destiny? Which of them has been restrained by the purer motive? Accordingly, where does the foundation of morality lie?