ūrdhvaḿ gacchanti sattva-sthā
madhye tiṣṭhanti rājasāḥ
adho gacchanti tāmasāḥ

Translation of Bhagavad Gita 14.18

Those situated in the mode of goodness gradually go upward to the higher planets; those in the mode of passion live on the earthly planets; and those in the abominable mode of ignorance go down to the hellish worlds.

Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:

In this verse the results of actions in the three modes of nature are more explicitly set forth. There is an upper planetary system, consisting of the heavenly planets, where everyone is highly elevated. According to the degree of development of the mode of goodness, the living entity can be transferred to various planets in this system. The highest planet is Satyaloka, or Brahmaloka, where the prime person of this universe, Lord Brahma, resides. We have seen already that we can hardly calculate the wondrous condition of life in Brahmaloka, but the highest condition of life, the mode of goodness, can bring us to this.

The mode of passion is mixed. It is in the middle, between the modes of goodness and ignorance. A person is not always pure, but even if he should be purely in the mode of passion, he will simply remain on this earth as a king or a rich man. But because there are mixtures, one can also go down. People on this earth, in the mode of passion or ignorance, cannot forcibly approach the higher planets by machine. In the mode of passion, there is also the chance of becoming mad in the next life.

The lowest quality, the mode of ignorance, is described here as abominable. The result of developing ignorance is very, very risky. It is the lowest quality in material nature. Beneath the human level there are eight million species of life—birds, beasts, reptiles, trees, etc.—and according to the development of the mode of ignorance, people are brought down to these abominable conditions. The word tamasah is very significant here. Tamasah indicates those who stay continuously in the mode of ignorance without rising to a higher mode. Their future is very dark.

There is an opportunity for men in the modes of ignorance and passion to be elevated to the mode of goodness, and that system is called Krishna consciousness. But one who does not take advantage of this opportunity will certainly continue in the lower modes.

Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:

According to the amount of sattva one can go upwards Brahmaloka.

Those in raja guna dwell on the human plane (madhye). Those of the lowest (jaghanya) guna with tamasic behavior like inattention and laziness, go to hell (adhah).

Commentary by Sri Ramanuja of Sri Sampradaya:

14.18 Thus, in the manner explained, those who ‘rest in Sattva rise upwards,’ namely, they attain liberation from the bonds of Samsara gradually. Those who, ‘abiding in Rajas’ which produces greed for heaven etc., engage themselves in actions which constitute the means for obtaining such results. Experiencing those results, they are born again and engage in, and perform, the very same acts. So they remain in the ‘middle’. This is mostly suffering, as it is characterised by rebirths. Those of Tamasic nature ‘stoop down’ into lower levels, as Tamas grows ever worse in them. They go ‘downwards’ i.e., to the lowest state among human beings, then to the condition of animals; then to that of worms; insects etc., then of immovable things, and even to the condition of shrubs and creepers, and ultimately to the condition of stones, wood, clod of earth, straw etc. Sri Krsna now teaches about the manner of those in whom the Sattva has gradually increased by adopting special holy food and performance of special disinterested deeds, and who thus rise upward by transcending the Gunas.

Commentary by Sri Sridhara Swami of Rudra Sampradaya:

Now Lord Krishna explains the various destinations of those situated in the three gunas or modes of material nature. Those who are predominantly in sattva guna or the mode of goodness ascend and can obtain according to the degree of excellence birth in the human worlds, the worlds of the Gandharvas who are the celestial singers and musicians. The worlds of the anscestors, the worlds of the demigods on up unto Satyaloka the world of Brahma which is the highest material realm. In the preceding examples the happiness that is experienced in each succeeding sphere is 100 times more potent than the preceding worlds. Those who are predominantly in raja guna or mode of passion, being overwhelmed by desires and attachment are only born again in the worlds of humans. Those who are predominantly in the darkness of tama guna or the mode of ignorance descend into lower existences taking birth according to the sinful deeds they committed in one of the 28 fiery hellish planets such as Tamisra reserved for those who steal anothers wealth and property or Rauvara the planet reserved for those who killed, sold, cooked or ate the flesh of animals.

Commentary by Sri Madhvacharya of Brahma Sampradaya:

Sri Madhvacharya did not comment on this sloka.

Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:

Now Lord Krishna speaks of the ascending stationary and descending spirals that He already began in verses 14 and 15. Those situated in sattva guna or the mode of goodness ascend to the heavenly spheres including the wordls of the ancestors, the worlds of the demigods etc. up onto Satyaloka the planet of Brahma. There by performing pious activities in the association of liberated beings they gradually perfect themselves and are freed from material existence and not subjected to accept samsara the perpetual cycle of birth and death. Those situated in raja guna or mode of passion who seeking rewards desire the pleasures of the heavens perform rituals to obtain such. After enjoying the temporary rewards for their endeavors and their punya or merits have been exhausted, they again are forced to suffer samsara over and over again due to greed for desires and attachment to pleasures of the flesh. Those situated in tama guna or mode of ignorance, whose consciousness is full of inertia and nescience and enveloped in darkness.They are full of degraded desires and degenerative impulses whose reactions caues them to sink deep into one of the 28 fiery hellish worlds such as Tamisra reserved for stealers of others wives and property and Raurava reserved for the killers, sellers, cookers and eaters of animals. Anyone who is a killer or eater of cows will definitely have Rauvara as their hellish destination where having received abundant punishment and suffering appropriate to their self induced previous sinful activities, they will take birth in the animal species as a dog, or pig, or even in lower species as an insect or worm.

Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:

14.18 Sattvasthah, people who conform to sattva, to the actions of sattva quality; gacchanti, go, are born; undhavam, higher up, in the worlds of gods and others. Rajasah, those who conform to rajas; [Those who are endowed with sense-knowledge and actions consequent on the preponderance of rajas.] tisthanti, stay, are born; madhye, in the middle, among human beings. Tamasah, those who conform to tamas, jaghanya-gunavrttasthah [A variant reading is vrttisthah.-Tr.], who conform to actions of the lowest quality of tamas, those who are attached to its actions-sleep, laziness, etc.-, the foolish; gacchanti, go; adhah, down, (i.e.) they are born among cattle etc. The association, owing to the false ignorance in the form of ‘being seated in Nature’, that an individual soul has with the gunas-in the form of happiness, sorrow and delusion, and which are matters of experience in such ways as, ‘I am happy,’ ‘I am sorrowful,’ ‘I am ignorant,’-that (association) is the cause of the individual soul’s mundane existence characterized by coming to have births in good and bad species. This was stated briefly in the earlier chapter. Elaborating that here in the text beginning with, ‘the qualities, viz sattva, rajas and tamas, born of Nature’ (5), the Lord has said that the nature of the qualities, the conduct conforming to the qualities, and the power to bind that the qualities have through actions conforming to them, and also the course of a person under the bondage, of behaviour conforming to the qualities,-all this is false knowledge; it has ignorance as its root and is the cause of bondage. Now, it is necessary to state that Liberation follows from right knowledge. Hence the Lord says:

Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:

14.16-20 Karmanah etc. upto asnute. Here, there are certain unconnected verses that have been concocted. They are of the nature of repetition, and hence they have to be necessarily rejected. A mode of life transcending these Strands turn to be nothing but emancipation.

Sanskrit Shloka Without Transliteration Marks:

urdhvam gacchanti sattva-stha
madhye tisthanti rajasah
adho gacchanti tamasah

Sanskrit to English Word for Word Meanings:

ūrdhvam — upwards; gacchanti — go; sattva-sthāḥ — those situated in the mode of goodness; madhye — in the middle; tiṣṭhanti — dwell; rājasāḥ — those situated in the mode of passion; jaghanya — of abominable; guṇa — quality; vṛtti-sthāḥ — whose occupation; adhaḥ — down; gacchanti — go; tāmasāḥ — persons in the mode of ignorance.