In the nidana chain, then, craving creates "fuel" for continued burning or becoming (bhava). The mind like fire, seeks out more fuel to sustain it, in the case of the mind this is "sense experience", hence the emphasis the Buddha places on "guarding the gates of the senses". By not being caught up in the senses ("appamāda") we can be liberated from greed, hatred and delusion. This liberation is also expressed using the fire metaphor when it is termed "nibbāna" (Sanskrit: "") which means to "go out", or literally to "blow out". (Regarding the word ", the verb "vā" is intransitive so no agent is required.)