Nyāya Sūtras 2.14

2.14

tac caitad uttarasūtreṇānūdyata iti/ heyam, tasya nirvartakaṃ hānam ātyantikam, tasyopāyo 'dhigantavya ity etāni catvāry arthapadāni samyag buddhvā niḥśreyasam adhigacchati/

And this is reiterated in the next aphorism: having correctly understood these four topics—that which is to be avoided, the cause of that, the ultimate cessation, and the means to that cessation which must be known—one attains the highest good.