If Rebirth is not taken literally then why seek Enlightenment?

“And if there is no rebirth, then the very goal of attaining nirvāṇa, understood as the cessation of rebirth, becomes almost perfectly meaningless. Or rather, nirvāṇa comes automatically to every living being that dies, regardless of how that being has lived.”

Hayes, Richard (1993). ‘Dharmakīrti on punarbhava’ In Egaku Maeda (ed), Studies in Original Buddhism and Mahayāna Buddhism. Kyōto: Nagata Bunshodo. Volume One, p. 111–30.

Consider the film Groundhog Day with Bill Murray, and his cycle of hedonism and depression as he lives the same week over and over again. Yet, you need not actually relive the same day to experience saṃsāra. For some unenlightened people, hell is a 9 to 5 job.

Rebirth is not taken literally when you don't believe in an existence of an absolute (non-relative) reality. In a thinking system where you consider reality literally , rebirth should be taken literally.

While a moment-to-moment interpretation of rebirth might be useful for insight practice, the Buddha actually was quite explicit in describing rebirth as a concrete physical process. A common stock phrase being used in many suttas:

...It's by reason of un-Dhamma conduct, dissonant conduct that some beings here, with the break-up of the body, after death, reappear in the plane of deprivation, the bad destination, the lower realms, in hell.. ...It's by reason of this Dhamma conduct & harmonious conduct that some beings here, with the break-up of the body, after death, re-appear in the good destinations, in the heavenly world. ~~ MN 41 ~~

Besides the other answers, rebirth and samsara can be interpreted from a psychological point of view.

The realms (or kingdoms) of samsara can be seen as mind states, and rebirth like the change of our lives.

Samsara, in short, represents the vicissitude of the human condition. Or in plain Buddhist, it shows us the impermanence of material and psychological states.

One day it is all good and happy, the next is not so good, than you feel OK, but something makes you upset, then you get a lot of work to forget those troubles and everything, then you start to feel better, but soon you start to feel stressed, and then you get a nice weekend, and so on. That's samsara, the ups and downs of life.

And about death and rebirth, you aren't the same person you were 10 years ago, and within 10 years you will be another person (if you keep on dying and rebirthing). In other words, the person of 10 years ago is dead, and now you are another one. And the person you are now, will be gone as you become another one.

One characteristic of Enlightenment is equanimity, that is, mental and emotional stability. Life will still have its ups and downs, but it won't be like a roller coaster, but more like a boat on a calm lake. And also, you won't rebirth anymore, in the sense that your personality and behavior will stabilize and you won't change from that.

The fundamental problem in most forms of Buddhism is suffering. If there is no afterlife, the problem of suffering can be solved with suicide. The historical Buddha's solution was tightly related to a realization about the nature of who we really are.

I am a secular Buddhist. I read other modern secular Buddhists and also think of solutions to the problem on my own.

Tom Pepper's Naturanlistic anatman, roughly says the the relevant unit of analysis is the collective consciousness. Individually, we don't exist, i.e. we lack certain desirable features of existence, such as a permanent, unchanging core. Collectively, we will live for a very long time, or at least until we render the planet uninhabitable. The goal is the liberation of this collective consciousness. Individual suicide will not help and killing everyone is impractical, to say nothing of the additional suffering it would create to even try.

Also, on my own, I've thought a lot about what the historical Buddha may have been like. He strikes me as a depressed young man who lived in a world where everyone around him said were he to die, he'd be right back in the miserable world again. He didn't go forth into homelessness because he was happy and well adjusted at home. Normally, we are eager to believe we are immortal. We fear death more than anything, so much so that we will tell ourselves any lie to convince ourselves of our immortality. If you are depressed, you want the pain to stop. Not surprisingly, many depressed people take euthanasia into their own hands. For the Buddha, were he to literally believe in reincarnation, even this won't help. But after meditating, he realized no part of himself was eternal. And consequence is that reincarnation and all beliefs in immortality of the self are bunk. Liberation is liberation from the belief in reincarnation. Further more, he realized that if he stop expecting things to last, he could gain some equanimity and peace and step out of the rat race. That state is nirvana, where you aren't exactly happy, but are in a comfortable state of anhedonia, something modern psychologists wouldn't think well of. The Buddha originally was going to keep his mouth shut about this realization, since he didn't think anyone would get it. Within in one generation, no one got it anymore. Nirvana was heaven and enlightenment was just the path to a better heaven in the old system of reincarnation. This process accelerated with arrival of Pure Land ideologies and the influence of Zoroastrianism in Mahayana and Hinduism in everything else.

As, Dzongsar Jamyang Khyenste Rinpoche, puts it

"If you don't believe in Rebirth, you are NOT a Buddhist; you are a materialist"

He recently (July 2015) gave a talk in Berkeley University on "Is there Buddhism without Rebith?" Answer is NO!. Here is a link to videos of the talk. Hope this helps.

Your understanding is correct - Buddhist seeks enlightenment in order to obtain emancipation from Samsara. There is NO other reason. All other reasons as invalid.

Existence is universal only. There is no individual existence. Life originates in favourable conditions. We got our life from parents. This is similar to a candle lighting another candle.WHen the former candle dies out, the flame passed out by the former candle lives in the other candles. Life comes from life only. It is due to our clinging towards our mistaken individual existence and fear of annihilation, that we believe in rebirth. Actually we are something which do not exist at all. Rebirth is in a wider perspective, similar to the concept of old leaves of a tree falling down and in its place new leaves appear. Here in the perspective of tree rebirths of leaves occur in a wider sense and not so in the case of individual leaves. The idea of rebirth is inducted to rely on the importance of karma and to prevent people from committing misdeeds. The individual existences die out but the world goes on. The World is like a plain paper in which different paintings appear and are removed one after the another.In the perspective of World we are nothing but negligible. So what more to say about our rebirth??

If Rebirth is not taken literally then why seek Enlightenment?

Because Enlightenment is at the top of Maslow's Pyramid. No matter what you do, no matter how satisfied you are, there is always something missing. We could almost say, sentient beings are pre-wired to want nothing less than Enlightenment.

“The true miracle is not to walk on water. The true miracle is to walk peacefully on the green earth, dwelling deeply in the present moment and feeling truly alive.”

― Thích Nhất Hạnh

Enlightenment is about peacefully walking here on this earth in the here and now. It isn't for the fruits of after-life though there's that angle to it. In my view it is worth the price of admission, if, in the here and now I can be less of a burden on others; and be compassionate and helpful to all around me. I view enlightenment as radical maturity and responsibility. It's not a supernormal power as much as an expertise of very human powers.

Lots of people equate enlightenment with magical powers, or perfection, or immortality, even though even the Buddha specifically made none of these a condition for arhatship. There were schisms in ancient Buddhist schools over this very point in the past.

I can't deny most accounts of the famous enlightened ones tend to emphasise that angle of better than human, but I think it is just commonplace elevation of the standard, just like most gyms tend to use a Mr. Universe kind of model for their advertising brochure. It's not a waste of time to go to the gym just because I am personally unlikely to become Mr. Universe. It's also not misleading, because with the right effort one can become so. We go to the gym to become healthy, if we can become even better, that's fantastic.

Growing less angry or sad, less lustful and grasping and more present and available to all beings is a useful way to live. If other positive attributes accumulate, that's even better.

"It's not that satori is unimportant, but it's not the part of Zen that needs to be stressed."

-- Shunryu Suzuki

Apropos rebirth:

Don't believe in the Buddha or science blindly. One says rebirth exists, the other says it's not proven even though there's periodically things that appear to be evidence for it. Enter samadhi and investigate for yourself.

In any case, someone who believes in rebirth is definitely going to be more responsible about their actions towards others and the planet than someone who firmly believes in you-only-live-once.

What then are other reasons for seeking enlightenment apart from the emancipation from Samsara?

In Samsara, the conditioned reality, everything exists due to causes and conditions.

Mental and physical phenomena are constantly arising and ceasing. They are ever-changing, uncontrollable and oppressive.

All conditioned phenomena follows a certain "order or recipe". I have made a drawing to illustrate this process. What can be seen here is that phenomena has 3 phases, i.e. Arising - Presence - Dissolution:

_{Click on photos for full size}

Even in the "presence-phase" phenomena are not stable or permanent but in a constant flux heading towards their own break up. Phenomena that exists due to causes and conditions are impermanent, meaning that they cannot be relied on. If one tries to rely on them or put trust in them, they will break up and leave one with only suffering and a void.

Nibbana is not caused or conditioned, it is unconditioned, unborn, uncaused, permanent, secure, stable. It does not rise and fall. It does not produce suffering.

Here is a description of Nibbana from the Buddha himself:

"Bhikkhus, I will teach you the taintless and the path leading to the taintless. Listen to that ...

"Bhikkhus, I will teach you the truth and the path leading to the truth ... I will teach you the far shore ... the subtle ... the very difficult to see ... the unaging ... the stable ... the undis­ integrating ... the unmanifest ... the unproliferated ... the peaceful ... the deathless ... the sublime ... the auspicious ... the secure ... the destruction of craving ... the wonderful ... the amazing ... the unailing ... the unailing state ... Nibbana ... the unafflicted ... dispassion ... purity ... freedom ... the unadhesive ... the island .., the shelter ... the asylum ... the refuge ...

-- SN 43: Asankhatasamyutta, p. 1378, Bodhi translation

The stable, the secure, the wonderful, freedom, the shelter.. I don't know about other beings, but these words/reasons seem pretty compelling to me.

Let's consider Andrei's definition of Buddhism, for example (because it's a short and easy definition).

Buddhists believe that human experiences originate in the mind, training which through cultivation of ethics, meditation, and wisdom leads to nirvana (the release from suffering) or enlightenment -- the insight into the true nature of things.

experiences originate in the mind

I think that, if you believe that experiences originate in the mind, then you might prefer Buddhism to other religions (which, tend to suggest that God is the creator; alternatively, atheistic views which suggest there is no creator): and then, if you are attracted to Buddhism for any reason, you might then align with or adopt Buddhist goals (e.g. for enlightenment).

cultivation of ethics

Similarly you might admire Buddhism's system of ethics (e.g. "don't kill", "don't steal", and "don't lie", etc.); and, you might prefer or choose those precepts instead of other religions' (whose most important commandments include for example "Thou shalt have no other gods before me").

nirvana (the release from suffering)

If (or assuming that) you are aware of suffering (or 'anxiety') in this life, isn't it true that "the release from suffering" is obviously (or self-evidently) desirable, in this life? You may not need to believe in rebirth, in order to want release from suffering (perhaps you do need to believe in suffering, though).

enlightenment (the insight into the true nature of things)

I'm not sure what this ('enlightenment' and 'insight') means, but I understand it to mean "having insight, can now help others to release themselves from suffering." Again, I think that wanting that probably only requires a belief in suffering and some compassion for others (i.e. you can want that for your sake and for other's sake regardless of whether and how you understand the word "rebirth").

In summary it's not necessarily only emancipation from samsara (i.e. the cycle of rebirth): it could be emancipation from dukkha; and also emancipation from the various kleshas, and fetters, and so on.

Whether or not they understand "rebirth", someone might feel a desire for refuge in this life.

I am a Rinzai Zen Monk with a decade-long monastic background so my answer will be relevant within our school's framework.

From a Zen POV being 'reborn' exists only within Reality. Reality is purely this one moment here and now. With each breath, with each action we are reborn. The choices we make are fresh and new. The Enlightened being will make those choices in accordance with what they experience. Because they are living in the here and now they are also making these choices without any reference to the past or the future because these are purely abstract concepts since neither of them is here and now.

The Enlightened person is literally reborn with each and every experience (in Japanese Zen terms these are known as 'Nen' - ie. the time it takes to register each experience). An Enlightenment experience is when you fully experience this for the first time: when a drop of water falling on your head or the call of a crow suddenly awaken you to this new awareness

There are other types of rebirth of course. Such as the delusional rebirths, when one succumbs to any of the poisons (Ignorance, Anger, Greed) and is reborn in 'hell'.

Buddhism is a very wide philosophy with a wide application of the same basic terms and concepts. What i have just said is not really valid for a Theravada Buddhist. It would be explained, understood and practiced differently by someone of a Pure land Path (JoDo ShinShu for instance) even though they are part of the Mahayana.