Compassion is certainly the opposite of selfishness, but you'd need to believe that individual selves exist as unities to dedicate yourself to helping any of them, whether it's yourself or a stranger. So it's belief in egoism as a metaphysical principle that supports compassion, and that conflicts with the cosmic perspective. Pure selflessness wouldn't be moralistic; rather, it would be transhuman lunacy, or wild, inhuman indifference towards anything.