Advaita Vedānta

These commentators read the verse as a verdict on metaphysical error: the tamasic person takes a single physical effect to be the whole reality. Their stock examples are the naked Jains (Kshapanakas), who hold the soul to be a thing inside the body and exactly the body's size, and the Charvaka materialists, who hold the body alone to be the self; they also name the worshipper who takes the Lord to be a mere lump of stone or wood. The contrast they draw is with the knowledge of the logicians, which grasps a self that is eternal and all-pervading, distinct from the body, and a Lord distinct from that. Tamasic knowledge fails precisely by 'non-grasping of eternality and all-pervadingness': it locks the self into the small, non-eternal, limited body. One of these voices is careful to add that the verse does not condemn the worship of any one form as such; what it condemns is the closing of vision in 'only this much is the self or the Lord'.

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

Viśiṣṭādvaita

These commentators read the single effect more concretely as a single kind of action, the worship of departed spirits and elemental beings, an action whose fruit is utterly slight. The tamasic person clings to this low worship as though it carried the fruit of the whole, when in truth it has no ground for such attachment. They keep the false-object point from their own system: the knowing here bears on a false object, the self conceived as joined with separateness and the rest. And they tie the smallness of the knowledge directly to the smallness of its chosen object: because its object is the worship of departed spirits and elementals, its fruit too is exceedingly small.

Rāmānujācārya · Vedānta Deśika

Śuddhādvaita

These commentators read the verse through devotion to the Lord and his play (lila). For one, the tamasic person is the one for whom the part is the whole and the petty god is the supreme; he too clings to the worship of ghosts and spirits with its exceedingly small fruit, and his knowing stands far from the steady seeing of the antaryamin, the inner ruler present in all beings, which only sattvic knowledge secures. For the other, the tamasic person clings to one form of the Lord's play without grasping it as the Lord himself manifest with the full richness of the lila; 'ahaitukam' is read as lacking the joy-experience that comes from awareness of the Lord behind every form, and 'lacking the real ground because lacking recognition of the Lord's appearance', so its fruit is narrow or even contrary.

Vallabhācārya · Śrī Puruṣottama

Bhakti

This commentator expands the verse into a vivid portrait of the tamasic mind as a creed cast out by all scripture, roaming like a lunatic with no restraints. He likens it to a stray dog devouring everything it can hold in its mouth, a forest fire that burns without discrimination, a crow that does not care whether its find is vomit or served food. Such knowing makes no distinction between the permitted and the forbidden, between holy and unholy waters, between eatable and uneatable; its only criterion is what pleases the palate and the senses. It takes the whole universe as its own wealth and food, takes the body for the soul and the stone idol for God, and treats merit and sin as bare lies. He concludes that calling this 'knowledge' is a misnomer, like calling a blind man's eyes fine; it is no real knowledge at all, only visual darkness.

Sant Jñāneśvar

Modern

This commentator reads the three kinds of knowledge as a single ascending scale of widening vision. Tamasic knowledge is the narrowest: it takes one's own wife and children as the entire world. Rising a little, one comes to count a fellow-townsman or fellow-countryman as one's own, while still seeing men of other places as different; that is rajasic. Rising higher still, one realizes that there is one Atman in all beings, and that knowledge is complete and sattvic. He frames the whole teaching as 'seeing unity in diversity', citing the Brihadaranyaka and Katha Upanishads that one who sees manifoldness falls into the cycle of birth and death. On this reading tamasic knowledge is simply the lowest rung of that ladder of synthesis.

Lokmanya Tilak

Modern

This non-sectarian devotional commentator turns the verse inward as a warning for the seeker's own practice. He marks the four phrases plainly: the man takes a single fragment of the field, his body or wealth or one preferred form, and treats it as if it were the totality; his regard is fixed on that one thing; he can give no reason for holding it so, only his own dullness; and the inquiry into what is real and what is shadow never enters. He insists this is the lowest grade of knowledge but still knowledge, knowing under the cover of tamas. His distinctive move is to make it personal: the seeker should watch for the trace of this in his own attitudes, since any feeling held in the 'I will only see this' manner, with no reason and no concern for truth, is itself tamasic.

Swami Ramsukhdas