In us mutual love is more agreeable because by such mutuality a greater reason for lovability is found in the thing loved. For any loved thing that is able to love makes itself more lovable, because the reason for lovability is not only whatever goodness is in it, but also the returned love (redamatio) is another reason for lovability, and for this reason someone having the goodness which is the first basis for lovability, and also the returned loved, is more lovable.
[Ordinatio 1.12.1, n. 33. This passage is quoted in Richard Cross's Duns Scotus on God, p. 218; I have changed Cross's translation at one or two points to make it a little easier to read.]
I deny, and reason as follows.
A thing may be lovable for a reason in two ways. First, the reason may constitute the thing as lovable; in this sense the reason for lovability is the goodness of the thing. In this sense also someone is more or less lovable as the reason is more or less. Second, the reason may confirm the thing as already lovable. In this sense, the adding of a reason for lovability does not make the beloved more lovable, but rather makes the love of the beloved richer and more certain. Now, in the case of a mutual love involving two people, it must be said that the returned love does not make the beloved more lovable, but confirms their lovability, in that the returned love is itself part of the goodness that is loved. Therefore it does not give an additional reason for the lovability of the beloved. However, it does add something to the love itself, namely, the mutuality, whereby the love is joined with a knowledge of being loved. And such love is therefore sweeter to the mind and is made more sure in the very act of loving. And thus we say that mutual love of two people is higher and greater than an unreciprocated love can be.
However, it is not only possible for mutual love to exist between two people, but also for there to be a mutual love of another, in which case there are at least three. Thus, in the love of a man, a woman, and their child, the man and the woman may love the child for the goodness in the child, and this is a constituting reason for lovability; however, their mutual love of the child does not make the child more lovable, but only makes the loving of the child sweeter and stronger than it would be were there no mutual love. Likewise, in the same case, the man and woman may love each other for the goodness in each, which is a constituting reason for lovability; however, their mutual love for the child does not make the other more lovable but confirms the lovability that already exists in each.
Now, it is true that a beloved who is able to love is thereby more lovable; but this is not relevant to the subject at hand, because the beloved's ability to love is not caused by the mutual love but a goodness in the beloved, and a very great one. The ability to love is therefore a constituting reason for the lovability of the beloved, for the ability to love is an eminent form of goodness. Thus, in cases in which we discover in the beloved a deeper ability to love, we rejoice, and love the beloved even more, because we have discovered that the beloved was more good than we had previously known. And this is especially true when the ability to love is an ability to share the love we have for some third thing. However, this ability is presupposed by any actual mutual love, and therefore cannot be an argument for the conclusion that mutual love is a constituting reason of lovability. And if you were to reply that the exercise of this ability must therefore also be a constituting reason for lovability, I reply that the ability to share love with another is simply the ability to love, and to know that the other loves, and the exercise of this ability is simply the exercise of those abilities. Thus the exercise of these abilities is a constituting reason for lovability, because it is a greater goodness in the beloved; but it is not a constituting reason as mutual love, but simply as love, for the mutuality of the love adds something to the notion of love, namely, the knowledge of a loved one's love for the same third. Thus there is no greater lovability constituted by the excercised ability to share in our love for a third than there is constituted by the exercised ability to love that third. However, in our case, the sharing of the love is a confirming reason, i.e., something that adds to the love itself (rather than to the lovability of the beloved or the mutually-loved).
Therefore it appears that mutual love does not, qua mutual, make either the beloved or the mutually-loved more lovable; rather, it makes the love a greater love than it would otherwise be.
[All of this is a fragment of a (very, very) rough draft for an argument. Scotus gives the above argument as a reason for denying the Augustinian and Victorine use of mutual love in discussion of the Trinity; he goes on to claim (rightly) that, since the Son is lovable in virtue of having the divine essence, than which no greater good is possible, he cannot be made more lovable in addition to any added thing. My argument is that Scotus is wrong to treat mutual love as something making the beloved more lovable; rather the idea in the mutual love argument is that mutual love is a greater love than solitary love. Scotus, of course, allows that there is mutual love between Father and Son; but he wants to treat this love as a shared love for the divine essence. In itself, however, this doesn't affect the mutual love argument unless you assume, as Scotus seems to, that this implies some additional lovability above and beyond the lovability of the divine essence. However, the mutual love argument is that mutual love is more agreeable than unrequited and solitary love, and the exercise of mutual love is itself something that is (as it were) already in the divine essence. For the mutual love argument is that God's love must be shared love. On a Victorine position, perfect love (amor iucundissimus) must involve a mutuality; it must be a concordant communion of love. Since God has perfect love by essence, divine love would have to involve mutuality. However, it's a subtle issue, and the above argument needs considerable refinement.]
