Perhaps I should say a few words about Buddhist philosophy by way of background.
The Buddhist approach to metaphysics is to avoid speculation about questions which cannot be determined. There are traditionally ten questions which are regarded as 'undetermined' (avyakaarta). It is not inferred that these questions cannot be answered by the Buddha, but that pursuing the answer to them is not conducive to liberation, to unbinding, to the cessation of suffering.
These ten questions are:
- Whether the world is eternal
- or not eternal
- Whether the world is finite
- or infinite
- Whether the soul and body are identical
- or different
- Whether the enlightened one exists after death,
- or does not exist after death,
- or both exists and does not exist after death,
- or neither exists nor does not exist after death
Even a cursory inspection of this list will reveal that a considerable amount of what is known in Western philosophy as the subject of metaphysics is either included or can be inferred from this list. (1)
Accordingly, such an approach naturally leads to a skeptical position. But the exact meaning of such skepticism is different to how we usually understand skepticism.
The modern skeptic basically has a naturalistic outlook. This means she is skeptical about any claims for which scientific or empirical evidence cannot be forthcoming.
Ancient skepticism was considerably different to that. It was born of an essentially religious view of the world. So it was skeptical about all kinds of 'worldly knowledge'. It was very much a renunciate philosophy. The Buddhist view of the world, as is well known, is that existence is 'dukkha', usually translated as 'suffering' or 'sorrowful'. This is the gist of the First Noble Truth. All beings are bound in 'samsara' which is the endless cycle of birth-and-death, due to their craving and ignorance. The remaining three Noble Truths, however, affirm that suffering, dukkha, has a cause, and that it can be ended, done away with, finished, the burden laid down, to put it in the traditional vernacular. It is important to state this, because many people have said that the Buddhist teaching is pessimistic. But it is not.
In Buddhist teaching, the proximate cause of suffering are greed, hatred and delusion. Basically these arise out of like, dislike, and indifference, magnified a thousandfold because of our attachment to what is essentially transitory. This is the state of the 'uninformed worldling', i.e. all of us.
But, unlike Platonism, and other forms of Idealist philosophy, Buddhism does not posit an ideal realm or a heaven realm as the result of the cessation of suffering. Instead it engenders a deep psychological transformation through attaining insight into the causes of suffering which arise from one's attachment to the transitory and empty objects of sensory experience.
In the Mahayana (or Northern) schools of Buddhism, however, this process of liberation does not mean leaving this world for a higher realm. In fact, the radical realization of the Mahayana is that Samsara and Nirvana are not different. 'Samsara is Nirvana grasped, and Nirvana is Samsara released', is the very succinct way of putting it. So it is more like a matter of transforming our view of this world, rather than realising an ideal or higher realm of experience. If you are familiar with the teachings of Zen Buddhism, this will not come as a surprise.
In practice, this results in an orientation towards action in the world, and engagement with the world, albeit with a radically different understanding of that same world. So in one sense it is a religious view, in that it takes seriously a religious discipline, ethics, and meditation, but on the other hand, it avoids the dichotomies and dualities that are so characteristic of the 'spiritual religions'. Instead it gives rise to what is known as 'the realization of emptiness' which arises when the practitioners sees the conditioned nature of all existence. Hence also the aversion to metaphysics in the Western sense which are felt to be grounds for 'dogmatic views'. (2)
It is also interesting to reflect that there is such thing as a skeptical faith. It seems a complete contradiction in Christian terms, but this only shows how conditioned we have become to a particular understanding of the meaning of religion in the western world.
Now, as for 'ground of being': this is an expression which is characteristic of various mystical teachings and also modern theologian Paul Tillich. I have found a nice quote on the idea, but it needs much reading to really get the idea.
God is not 'out there'. He is in Bonhoeffer's words ' the "beyond" in the midst of our life', a depth of reality reached 'not on the borders of life but at its centre', not by any flight of the alone to the alone, but, in Kierkegaard's fine phrase, by ' a deeper immersion in existence'. For the word 'God' denotes the ultimate depth of all our being, the creative ground and meaning of all our existence. ...Tillich warns us that to make the necessary transposition, 'you must forget everything traditional that you have learned about God, perhaps even that word itself.'
This kind of understanding is characteristic of the understanding of monastics and practitioners. But it is a state of being. You have to walk the walk, and it is a tough thing to learn.
(1) In fact it is interesting to compare some of the items on this list with Kant's 'antinomies of reason'. Some scholars believe that the Buddhist approach to metaphysics is similar to Kant's in these respects, with the caveat that they are derived from vastly different historical and cultural backgrounds. See The Central Philosophy of Buddhism
by T R V Murti.
(2) In fact, there are strong grounds for saying that Mahayana Buddhism directly informed the Greek Skeptics, particularly Pyrrho, who travelled to India and subsequently exhibited a very Buddhist style of argumentation. These themes are explored in the excellent The Shape of Ancient Thought
, by Thomas McEvilly.