So what is this Enlightenment that is the goal of Buddhist practice - but which we’re not supposed to crave? To a great extent it depends on what school of Buddhism you follow.
In Theravada it is a personal goal to be achieved over multiple lifetimes - and generally only once you have been reborn in a life where you can become a monk or nun (and even nun is questionable in some Theravada texts). Here it is usually seen as the extinguishment of the ego, yet if that were true then the Buddha shown in the Canon was not Enlightened for he certainly still had ego identity. Perhaps it could better be phrased as the extinguishment of clinging to the ego.
In Mahayana it is that toward which we work for the good of all beings, not just for ourselves. Also, as Buddhism penetrated China and the Japan and encountered their native religions it began to be viewed less and less as an end goal to be achieved and more as a process - a path. This is why it so easily became identified with the Tao. Enlightenment had become a verb rather than a noun.
Taoism has gained an undeserved reputation as a passive, non-reactive, non-contentious philosophy and this has to a great extent been expanded to include Zen as well - and here when I use the term Zen I use it to include both Japanese and Chinese Buddhism as did Dogen. It is in fact both non-reactive and non-contentious; but that does not imply that it is passive. It is in fact - as is Zen - incredibly active and alive. Eubanks sensei says,
To “not contend” is not a denial of action, but rather it is an attitude of mind that says, “I am completely related to this person/situation and have to deal with it as it is presented to me.” When we run in to difficult people or situations in our daily lives, we can maintain or regain control ourselves and the situation only if we accept the nature of our relationship to it: we are not separate from the people and situations that distress us.
Stephen Batchelor in his latest book, “After Buddhism” indeed labels the cessation of reactivity as the very definition of nirvana in his reformulation of the Four Noble Truths as the Fourfold Task. This cessation - this experience of nirvana - is the third step in the task and is the motivating factor in moving on to the fourth - following the eightfold path to make it not a momentary experience but the grounding state of our life.
This is actually very consistent with the actual working out of Zen - especially in Japan. Satori, or Enlightenment - was the experience of our relationship with the world around us in a non-reactive way. Whether it was seen to come in a flash or through steady work and practice it was not necessarily a state that one achieved once and for ever. It was not something that made an ontological change in a person. Dogen, for example, was certified in satori before he even began the journey to China that resulted in the foundation of Soto Zen - part of our own lineage. If satori were a one-time change to an Enlightened State as an ontological change he would not have been driven to find a new way of practice and a new philosophy that answered his questions with the current Buddhism in Japan. This view is also reflected in the Zen poem:
Before Enlightenment chop wood, carry water.
After Enlightenment chop wood, carry water.
Enlightenment - we usually use the term Realization in PB, but I actually prefer the term Satori since sometimes when you use a foreign term you don’t get bogged down in the existing understanding of English words - should be understood in our teachings to be the cessation of reactivity in our responses to the world around us. This may be a momentary experience - indeed it will almost certainly start that way - but it should be just the start of your journey, not the end. It might be compared to the first time you fell in love - real love. It might have knocked you off your feet but you came out not wanting to sit there as it was but to see it grow and become more powerful.
It is, indeed sitting in satori that is the danger and the snare. We cannot cling to a satori moment but have to take the next step in the Fourfold Task and move on to committing ourselves to the Eightfold Path so that we work this enlightenment out in the world - as did the Buddha. To cling to our Enlightenment is to return to reactivity and so to lose our enlightenment. This is not some mystical riddle but simple truth. Satori does not exist without the world we live in. It is not a retreat or escape from the world but the true working out of our authentic relationship with the world.