शमो दमस्तपः शौचं सन्तोषः क्षान्तिरार्जवम् ।
ज्ञानं दयाच्युतात्मत्वं सत्यं च ब्रह्मलक्षणम् ॥ २१ ॥
satyam ca brahma-laksanam
samah-control of the mind; damah-control of the senses; tapah-austerity and penance; saucam-cleanliness; santosah-satisfaction; ksantih-forgiveness (being unagitated by anger); arjavam-simplicity; jnanam-knowledge; daya-mercy; acyuta-atmatvam-accepting oneself as an eternal servant of the Lord; satyam-truthfulness; ca-also; brahma-laksanam-the symptoms of a brahmana.
The symptoms of a brahmana are control of the mind, control of the senses, austerity and penance, cleanliness, satisfaction, forgiveness, simplicity, knowledge, mercy, truthfulness, and complete surrender to the Supreme Personality of Godhead.
In the institution of varnasrama-dharma, the symptoms of a brahmana, ksatriya, vaisya, sudra, brahmacari, grhastha, vanaprastha, and sannyasi are all described. The ultimate aim is acyutatmatvam-to think always of the Supreme Personality of Godhead, Krsna, or Visnu. To make advancement in Krsna consciousness, one has to become a brahmana, with the above-mentioned symptoms.