The resolute understanding is single; the irresolute mind branches without end.

Advaita Vedānta

These commentators read the resolute understanding as the certainty of the truth of the self, the discerning conviction 'I am Brahman' that arises from the great Vedic sentence and is produced by a sound means of knowledge. This one conviction sublates every contrary mental modification. Its fruit is decisive: when the endlessly divided understandings cease, transmigration too comes to rest, for it is the branching variety of contrary understandings that keeps samsara wide, shoreless, and perpetually stretched out. One of them adds a further distinction within the path: the knower of Brahman, being all-accomplished, has no lingering 'fall-doubt,' no fear of slipping back, whereas the irresolute, not knowing for sure what his good is, remains exposed to it. On this reading the verse is finally about saving knowledge: the single resolve is the realization that ends the whole machinery of rebirth.

Śaṅkarācārya · Śrī Ānandagiri · Madhusūdana Sarasvatī · Śrī Nīlakaṇṭha · Dhanapati Sūri

Viśiṣṭādvaita

These commentators read the verse within the discipline of action performed by a seeker of liberation. The resolute understanding is the understanding to be used in all scripturally ordained action, and it is preceded by certain ascertainment of the self's true nature; it is one because it has for its object the means to a single fruit, liberation. They press a careful contrast with desire-prompted action: there, only the bare existence of a self distinct from the body is needed, not the full truth of the self, since craving for heaven, the means to it, and the enjoyment of it all remain possible without deeper knowledge. The teaching they extract is concrete and integrative: obligatory and occasional actions, with their principal and secondary fruits given up, are to be performed as having liberation for their one aim; even desire-prompted actions suited to one's station are to be merged into this, their separate fruits surrendered, and performed according to capacity. The many-branchedness of the irresolute is then the endless secondary fruits heard of in the texts, long life, good offspring, and the rest, multiplying even within one rite.

Rāmānujācārya · Vedānta Deśika

Dvaita

These commentators give the verse a distinctive epistemic reading. They take it as Krishna's answer to a real worry Arjuna would feel: understandings are many because doctrines differ and contradict one another, with no obvious ground for deciding 'just this is true and not that,' so how is one to fix one's trust in a single view, in Krishna's word alone? The reply is that 'resolution' here means being settled as authoritative, not mere subjective certainty. Doctrines settled by a sound means of knowledge simply agree with one another and never conflict; that harmonious, well-grounded view is the one to accept. They explicitly reject the objection that every view is 'resolute' because each holder feels no doubt in his own matter: private confidence is not the point. Only the view grounded in valid knowledge is single and conflict-free, which is exactly why a thoughtful person finds no firm footing among the many ungrounded, mutually warring opinions.

Madhvācārya · Śrī Jayatīrtha

Bhedabheda

This commentator's note here speaks to the crossing beyond the suffering of worldly existence by action joined with understanding, and remarks that some texts read 'approach' for 'crossing,' with the meaning unchanged. He does not develop the contrast of single versus many-branched understanding that the other schools draw from this verse; his gloss stays with the theme of action united with understanding as the means of crossing over.

Śrī Bhāskara

Kashmir Shaivism

This commentator's note here dwells on the assurance that in this understanding there is no loss through transgression, fault, or heedlessness, because heedlessness is absent. He offers a vivid image: just as a blazing cauldron of oil is at once cooled by a single measured grain of sandal, so by this yoga-understanding, slight though it be, the great fear that is transmigration is destroyed. His emphasis falls not on the contrast of one versus many but on the safety and disproportionate power of even a little of this steady understanding.

Ācārya Abhinavagupta

Bhakti

These commentators read the path here as the Lord's worship, and the resolute understanding as the conviction of devotion. One states it plainly as 'I shall certainly cross over,' and makes the strong move of identifying vyavasaya, resolve, with parameshvara-bhakti itself, so that single-pointedness and devotion become one thing. Another voices it as a whole-hearted vow: the chanting, remembrance, and service of the Lord taught by one's teacher is at once my means, my end, and my very life, never to be abandoned in either state, with no other thing desired even in a dream, so that one is unmoved whether happiness or pain or even endless rebirth come. A third frames the singleness as the superiority of desireless action done as worship of the Lord, aimed at the one fruit of experiencing the self; and a fourth praises this God-directed intellect as the one real intellect in the world, rare as a wishing-stone or a drop of nectar, beside which all other thoughts only win heaven, the world, and hell, but never a glimpse of the self's bliss. For all of them the one resolute understanding is the devotee's settled heart.

Śrīdhara Svāmī · Śrīla Viśvanātha · Śrīla Baladeva · Sant Jñāneśvar

Śuddhādvaita

These commentators read the single resolute understanding on the path of bhakti as the specific conviction 'I shall act only by the Lord's command,' as one who belongs to the Lord. Those who work for fruit have minds scattered in many directions and outward-facing hearts, so their intellects fork endlessly for the sake of results; and because their state is incomplete, the danger of mishap is genuine. The devotee's state, by contrast, is complete, so no such fruitlessness can befall it. One of them seals this with the Lord's promise that if those who work for Him should ever suffer a lapse, great seers in their crores will do the work for them, so the devotee's single resolve can never come to nothing.

Vallabhācārya · Śrī Puruṣottama

Modern

These commentators stay close to the psychology of the verse. One makes a careful philological point: in this line buddhi, qualified by 'resolute,' means the organ of Reason that discerns the doable from the not-doable and must be made one, that is, concentrated; but in the second line buddhi stands alone and means the desires or flights of imagination, which in the unsteady person multiply into ever new waves, chasing a son today and heaven tomorrow. Another locates the singleness in renunciation: the one definite resolve is to give up craving for the world and gain the supreme reality, and this resolve is one precisely because giving-up is single, whether one drops the craving for wealth or for honor, while taking is many, since the objects of desire and so the cravings for them are endless. A third describes the yogi gathering all the dissipated rays of the mind through discrimination, dispassion, and concentration, free from wavering, and notes that if thoughts cease, samsara ceases, since names, forms, and thoughts are inseparable. A fourth puts the loss plainly: when the one settled will breaks up into many divided wills of desire, a person is simply tossed about among them.

Lokmanya Tilak · Swami Ramsukhdas · Swami Sivananda · Mahatma Gandhi