I have been looking for a good discussion of Sikh virtue theory for ages now, and I have finally found one: Keshav Singh's "Vice and Virtue in Sikh Ethics", which is short but beautifully clear introduction to the essential concepts:
Part of this ethics, I will argue, is a theory of vice and virtue that is not only of historical and religious interest, but holds up to Western theories in plausibility and systematicity.
According to this theory, there is a unity of vices – in other words, there is a sort of master vice in virtue of which all other vices are vices. This master vice is the vice of haumai, which is a central ethical concept in Sikhism. On the view that emerges, haumai is the source of human beings’ separation from an ultimate reality in which we are radically interconnected, both metaphysically and ethically. The five primary vices are all forms of haumai, and all stem from a false sense of self-importance. Vice, then, comes down to the failure to recognize the importance of others. The corresponding picture of virtue is that virtue consists in a recognition of the importance of others, through the recognition of an ultimate reality on which all are One. While the vicious person is, at the extreme, a kind of ethical solipsist, the virtuous person is an ethical universalist, treating all others as bearers of the same value she herself has.
Highly recommended, if you have an interest in either virtue ethics or comparative philosophy.