Link to purport by A C Bhaktivedanta Swami Srila Prabhupada

Transcript of Bhakti-Shastri class on this verse by Chaitanya Charan

Now Krishna will give some generic definition of what happens when

Bg 14.18

ūrdhvaṁ gacchanti sattva-sthā
madhye tiṣṭhanti rājasāḥ
jaghanya-guṇa-vṛtti-sthā
adho gacchanti tāmasāḥ

Synonyms: 

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.

Translation: 

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.

Here Krishna has not even called mode of ignorance but He has mentioned jaghanya-guṇa-vṛtti, 

ūrdhvaṁ or up refers to higher lokas or more elevated consciousness 

down refers to lower planets or lower species, mūḍha-yoniṣu jāyate as discussed in 14.15, adho gacchanti.

SP Purport: The result of developing ignorance is very, very risky. That means to lose human form because we don’t know when we will again get human form.

End of transcription.