It is a quite natural tendency of human nature to fixate on one issue to the exclusion of others. The mind, as a dividing and analyzing instrument, tends toward exclusive concentration. So it is easy to understand that when we once focus on the ethical principle, that it may be viewed as the “categorical imperative” of our human nature.
Sri Aurobindo acknowledges the role of the ethical principle, but he also puts it in context with other aspects of our nature that equally call for fulfillment. There are the seeking for knowledge, the seeking for beauty and harmony, the seeking for Oneness which also represent aspects of our nature.
Sri Aurobindo takes up this question: “The Indian thinkers had a wiser sight who while conceding right ethical being and conduct as a first need, still considered knowledge to be the greater ultimate demand, the indispensable condition, and much nearer to a full seeing came that larger experience of theirs that either through an urge towards absolute knowledge or a pure impersonality of the will or an ecstasy of divine love and absolute delight,–and even through an absorbing concentration of the psychical and the vital and physical being,–the soul turns towards the Supreme and that on each part of our self and nature and consciousness there can come a call and irresistible attraction of the Divine. Indeed, an uplift of all these, an imperative of the Divine upon all the ways of our being, is the impetus of self-enlargement to a complete, an integralising possession of God, freedom and immortality, and that therefore is the highest law of our nature.”
Sri Aurobindo, Rebirth and Karma, Section III, Chapter 16, The Higher Lines of Karma, pp. 148-149, http://www.lotuspress.com/item.php?item=990117