I think the middle way is to maintain the noble eightfold path without being caught up on the dualities that language tends to impose. The most common duality cited in this discussion is pleasure/pain, but it's also easy to be caught up on dualities like gain/loss, existence/nonexistence, etc. Aside from their relevance in learning the skills of ending suffering, the dualities are irrelevant. It's a "middle" not because the scale is balanced on both sides so much as because the scale is completely ignored. The problem is understanding stress, abandoning the causes of stress, realizing the cessation of stress, and developing the path to the cessation of stress. Labeling the world with dualities is beside the point.http://www.accesstoinsight.org/tipitaka/sn/sn56/sn56.011.than.html
SN56.11: Dhammacakkappavattana Sutta wrote:"There are these two extremes that are not to be indulged in by one who has gone forth. Which two? That which is devoted to sensual pleasure with reference to sensual objects: base, vulgar, common, ignoble, unprofitable; and that which is devoted to self-affliction: painful, ignoble, unprofitable. Avoiding both of these extremes, the middle way realized by the Tathagata — producing vision, producing knowledge — leads to calm, to direct knowledge, to self-awakening, to Unbinding.
"And what is the middle way realized by the Tathagata that — producing vision, producing knowledge — leads to calm, to direct knowledge, to self-awakening, to Unbinding? Precisely this Noble Eightfold Path: right view, right resolve, right speech, right action, right livelihood, right effort, right mindfulness, right concentration. This is the middle way realized by the Tathagata that — producing vision, producing knowledge — leads to calm, to direct knowledge, to self-awakening, to Unbinding.
Bhikkhu Bodhi: The Noble Eightfold Path: The Way to the End of Suffering wrote:To eliminate ignorance we need wisdom, but how is wisdom to be acquired? As indubitable knowledge of the ultimate nature of things, wisdom cannot be gained by mere learning, by gathering and accumulating a battery of facts. However, the Buddha says, wisdom can be cultivated. It comes into being through a set of conditions, conditions which we have the power to develop. These conditions are actually mental factors, components of consciousness, which fit together into a systematic structure that can be called a path in the word's essential meaning: a courseway for movement leading to a goal. The goal here is the end of suffering, and the path leading to it is the Noble Eightfold Path with its eight factors: right view, right intention, right speech, right action, right livelihood, right effort, right mindfulness, and right concentration.
The Buddha calls this path the middle way (majjhima patipada). It is the middle way because it steers clear of two extremes, two misguided attempts to gain release from suffering. One is the extreme of indulgence in sense pleasures, the attempt to extinguish dissatisfaction by gratifying desire. This approach gives pleasure, but the enjoyment won is gross, transitory, and devoid of deep contentment. The Buddha recognized that sensual desire can exercise a tight grip over the minds of human beings, and he was keenly aware of how ardently attached people become to the pleasures of the senses. But he also knew that this pleasure is far inferior to the happiness that arises from renunciation, and therefore he repeatedly taught that the way to the Ultimate eventually requires the relinquishment of sensual desire. Thus the Buddha describes the indulgence in sense pleasures as "low, common, worldly, ignoble, not leading to the goal."
The other extreme is the practice of self-mortification, the attempt to gain liberation by afflicting the body. This approach may stem from a genuine aspiration for deliverance, but it works within the compass of a wrong assumption that renders the energy expended barren of results. The error is taking the body to be the cause of bondage, when the real source of trouble lies in the mind — the mind obsessed by greed, aversion, and delusion. To rid the mind of these defilements the affliction of the body is not only useless but self-defeating, for it is the impairment of a necessary instrument. Thus the Buddha describes this second extreme as "painful, ignoble, not leading to the goal."
Aloof from these two extreme approaches is the Noble Eightfold Path, called the middle way, not in the sense that it effects a compromise between the extremes, but in the sense that it transcends them both by avoiding the errors that each involves. The path avoids the extreme of sense indulgence by its recognition of the futility of desire and its stress on renunciation. Desire and sensuality, far from being means to happiness, are springs of suffering to be abandoned as the requisite of deliverance. But the practice of renunciation does not entail the tormenting of the body. It consists in mental training, and for this the body must be fit, a sturdy support for the inward work. Thus the body is to be looked after well, kept in good health, while the mental faculties are trained to generate the liberating wisdom. That is the middle way, the Noble Eightfold Path, which "gives rise to vision, gives rise to knowledge, and leads to peace, to direct knowledge, to enlightenment, to Nibbana."