hatha yoga pradipika 1400CE

“Yoga perishes by these six: overeating, overexertion, chattering/gossiping, needless austerities, socializing, and restlessness. Yoga succeeds by these six: enthusiasm, openness, courage, knowledge of the truth, determination, and solitude.”

Hatha-Yoga-Pradipika 1.15-16 [by Svatmarama, translation Brian Akers]