Jñāna
What counts as liberating knowledge?
Jñāna is the knowledge that liberates. The question is what that knowledge itself is.
Advaita and Viśiṣṭādvaita agree that ritual duty alone does not bring about the highest human good. Beyond that, all three traditions understand very differently what liberating knowledge itself is: for Advaita, a direct comprehension of Brahman as one's own Self; for Viśiṣṭādvaita, sustained meditative attention that is itself the deepest form of knowing; for Dvaita, the direct seeing of Brahman, to which meditation is the means.
How each commentator reads it
Direct comprehension of Brahman as one's own Self, arising from a valid means of knowledge (Scripture, ultimately confirmed by intuition) encountering an already-existing object. It is not an activity, not something enjoined or produced by effort, and not dependent on any accompanying practice for its liberating effect. Once arisen, this knowledge alone terminates Nescience.
Read Śaṅkara’s interpretation →The liberating knowledge of Brahman is not mere apprehension of a sentence's meaning, but must take the form of sustained meditation (dhyana/upasana): direct, continuous contemplative attention on the Self/Brahman, joined with the grace of the Lord, who is pleased by the devotee's meditation. Bare propositional cognition of 'Thou art that' does not, by itself, terminate bondage.
Read Rāmānuja’s interpretation →Liberating knowledge is the direct seeing of Brahman, the Lord, which arises when meditation, practised after study and reflection, is completed. Once arisen it is never lost; it is the condition of the Lord’s full grace; and from it the accomplishment of all ends proceeds.
Read Madhva’s interpretation →About the evidence
All three commentators comment directly on Brahma Sūtra 3.4.1. Śaṅkara and Rāmānuja agree that the highest benefit does not come from ritual duty alone; they differ over what the direct means is, Śaṅkara identifying it with independent knowledge of Brahman and Rāmānuja with meditation, understood not as something opposed to knowledge but as the form liberating knowledge takes. Madhva reads the sūtra as saying that all ends proceed from the seeing of Brahman, for which meditation is the means laid down.
This comparison draws on a small, closely read set of passages rather than everything either tradition says about knowledge. It is enough to show a genuine point of contact and contrast, but not a complete account of either tradition's teaching.