Dogen's Shobogenzo is, in the main, notoriously difficult. Two factors are the diffculties of translating from Japanese language to English and medieval Japanese-Chinese Buddhist references to a contemporary audience, but his philosophy and presentation are also quite obscure in themselves. Sometimes I wonder who he had in mind as his audience. I don't count myself as an authority or expert here but, drawing on many sources, this is my interpretation - an interpretation which is provisional and probably always will be.
The Genjo koan is possibly the most heavily quoted and important text within the Shobogenzo. Most of the key themes of Dogen's philosophy are exposed here:
the relationship between conventional and ultimate truths in Buddhism
the relationship between delusion and awakening
the relationship between relative and absolute
The nature of the self, life and death in terms of 'Being-time'
Dogen's Great Doubt - if we already have Buddha Nature why do we need to practice?
I'm using the Robert Aitken and Kazuaki Tanahashi translation. There is a very useful webpage here which allows direct comparison of 8 different translations. I'll be posting this in several sections.
As all things are buddha-dharma, there are delusion, realization, practice, birth and death, buddhas and sentient beings. As myriad things are without an abiding self, there is no delusion, no realization, no buddha, no sentient being, no birth and death. The buddha way, in essence, is leaping clear of abundance and lack; thus there are birth and death, delusion and realization, sentient beings and buddhas. Yet in attachment blossoms fall, and in aversion weeds spread.
This section is about the relationship between the conventional and ultimate teachings of Buddhism.
In Dogen's time and in our own, we typically come across the Buddhist teachings in two forms. Firstly, the conventional religious teachings most especially as presented in the Pali Canon, in which we are taught the Four Noble Truths, the distinction between delusion and realisation, life and death, suffering and the path to end suffering. Secondly, and especially from the Mahayana Prajnaparamita sutras we have teachings that apparently contradict the conventional teachings. As the Heart Sutra says:
Nothing is born, nothing dies,
nothing is pure, nothing is stained,
nothing increases and nothing decreases.
So, in emptiness...
There is no ignorance,
and no end to ignorance.
There is no old age and death,
and no end to old age and death.
There is no suffering, no cause of suffering,
no end to suffering, no path to follow.
There is no attainment of wisdom,
and no wisdom to attain.
Is this a real contradiction or just the revelation of another, perhaps deeper truth? And how do we reconcile these apparently contradictory teachings?
This also takes us to the 'Great Doubt' that Dogen travelled to China to resolve: If we already have (or 'are' in Dogen's language) Buddha Nature - and this is not mere potential - why do we need to practice at all?
As all things are buddha-dharma, there are delusion, realization, practice, birth and death, buddhas and sentient beings.
The first sentence is the Buddhist world-view from the conventional, conceptual or dualistic perspective - the perspective of differentiation, that is, from the ordinary human way of looking at things. This corresponds to the Buddha-dharma as described in most of the Pali Canon. There is a difference between delusion and realisation, birth and death, Buddhas and ordinary beings and it seems that Buddhism is about the progression from one condition to another.
[Note: The very first phrase As all things are buddha-dharma... is quite difficult to interpret. Do we interpret as 'Since all things are Buddhism' or 'when all things are seen as Buddhism' or 'if all things are seen as if they were Buddhism'? I suspect the former. To see everything as Buddhism (or Buddha) is to see all things in terms of Buddhist convention.]
As myriad things are without an abiding self, there is no delusion, no realization, no buddha, no sentient being, no birth and death.
This is reality from the ultimate, non-conceptual, non-dualistic perspective - the perspective of emptiness, as described with the philosophy of negation used in the Prajnaparamita sutras and the Madhyamaka philosophers. Buddha taught that no phenomena have or are a self. Nagarjuna explored this deeply in his Mula Madhyamaka Karika.
Neither from itself nor from another,
Nor from both,
Nor without a cause,
Does anything whatever, anywhere arise.
Entities have no independent identity, they do not exist as absolute entities, thus in that sense they are not entities at all - so ultimately there is no delusion, no realisation, no Buddha, ordinary beings, birth or death. These are not inherently real distinctions, they are fabrications.
The buddha way, in essence, is leaping clear of abundance and lack; thus there are birth and death, delusion and realization, sentient beings and buddhas.
So how do we reconcile these apparent opposites? Do we hold to the teaching of emptiness as the final superior truth? The teaching of emptiness or 'No this or that' is not ultimately real either - it too is a fabrication, another conventional designation and is a problem if it is clung to and seen as a denial of reality. And the apparent duality of conventional and ultimate is a dualistic fabrication too.
(To say) "Is," is eternity-grasping; (to say) "Is not," is a nihilistic view...
Although (the term) "self" is caused to be known (of, about), and although (a doctrine or teaching of) "no self" is taught,
No "self" or any "nonself" whatsoever has been taught by the Buddhas.
The designable is ceased when/where the range of thought is ceased...
"Empty" should not be said (or "would be impossible to say"), nor should "Nonempty",
nor "both and neither"; but they are spoken of for the purpose of praj~naptification..
Whatever is dependently co-arisen / That is explained to be emptiness.
That, being a dependent designation, / Is itself the middle way.
Something that is not dependently arisen / Such a thing does not exist.
Therefore a non-empty thing / Does not exist...
There is nothing whatsoever of samsara distinguishing (it) from nirvana.
There is nothing whatsoever of nirvana distinguishing it from samsara.
(That?) is the limit which is the limit of nirvana and the limit of samsara;
Even a very subtle interval is not found of (between) them...
There is no dharma whatsoever taught by the Buddha to whomever whenever, wherever.
- from Nagarjuna's MMK
The place where all dualities are reconciled is in reality itself, which is beyond grasping by thoughts and language. The essence of Buddhism transcends existence and non-existence and transcends differentiation and non-differentiation. Reality is neither absolute existence nor is it non-existence. It is a continual unfolding without anything fixed.
And yet it is only because phenomena are empty that they are real phenomena. It is only because they are not fixed natures that they can arise and have their (relative) existence and potency in the world - that change and differentiation are possible.
In reality the totality and the particular always arise and express themselves together. There are no waves apart from the ocean and no ocean apart from the waves. In this way all beings already [i]are [/i]Buddha Nature. The particular are not at all separate from the universal.
Yet in attachment blossoms fall, and in aversion weeds spread.
Even though all beings are already Buddha Nature - and this is fully real and not just a potentiality - this reality alone does not solve the problem of suffering. Except for the problem of suffering - the First Noble Truth - Buddhism would be unneccessary. The Second Noble Truth is that suffering is craving for things to be other than they are. We react to circumstances we like by trying to hold onto them, yet because they are impermanent and ultimately unfulfilling we suffer. We react to circumstances we dislike by trying to push them away, destroy them, escape from them or wish them away, but we can't. We can never change the moment we are in right now (the only moment that is real) and the urge to do so is suffering. In this way, delusion about our true nature causes attachment and attachment causes suffering.