The answers you get to this will depend on who formulates the response. The sleek 30-something clad in organic cotton leggings with a healthy glow might answer, while holding “plank pose” for an excruciating length of time, that yoga is about being simultaneously buff and chilled out. Ask a grizzly old Hindu monastic like myself and you’re likely to get a more knotty and byzantine response.
We humans are explorers. As soon as we stood upright we set out to explore the planet, taking fire with us. In the Shanidar cave high on the Bradost mountain of Iraq, rest skeletons respectfully laid in a foetal position, on beds of flowers gathered from the valley below. Each skeleton has artefacts useful for an afterlife carefully placed to hand. They may date back as far as 65,000 years and belonged to Neanderthals. Thus it seems that all branches of humanity were explorers, peering into the veil of death. We have always asked questions such as “What is all this?” and “Where did it all come from?”, and, most maddening of all, “Who am I?” That, we can speculate, is how all religion, philosophy and science were born. That is how yoga was born.

Now, as ever, we live poised at the edge of an abyss, not knowing what the next moment will bring. And in this age of the ascendancy of science, that edge has grown closer – and the abyss deeper – in our consciousness: we are a “biological accident”, so nearly not, and yet here we are, crying out like the poet Rabindranath Tagore: “When should I find myself complete in myself?”

In India, once the ancient hymns and rituals of the Vedas (the cornerstone texts of Hinduism) had been formulated, and once the great Indus Valley civilisation had risen and turned to dust, a group of people, women as well as men, gave up the cities and went into the forests – to become known as the aranyakas (forest dwellers). The core ritual of the Vedas was the sacred fire ceremony. The aranyakas internalised exploration, taking the heat and light of their sacred fire into the darkness within as they sought to understand consciousness. In the forests they contemplated truths that had been handed down for centuries by word of mouth. Their contemplations became the final portion of the Vedas, called the Upanishads. It is the Upanishads that crystallised the teachings of yoga.

The word Upanishad means, roughly, teachings received when you have drawn close: they are for dedicated students, the seekers who hang around asking persistent questions. The Katha Upanishad is one such teaching, in which a young seeker becomes disillusioned with the status quo and as a consequence is condemned to death. In a dialogue with death he is given the very first recorded teaching of yoga as a means of understanding life.

This teaching begins by acknowledging that, “moment by moment”, we are faced with choosing a more meaningful response than our habitual knee-jerk reaction. This, then, is the first definition of yoga: walking through the fire of refusing our first reactions, knowing that while we might not choose our circumstances, we can choose our responses to them.

Many Upanishads continued this exploration of yoga, but around 250 BCE (a date not set in stone) a remarkable philosopher delineated the quest of yoga in what has become known as the Patañjali Yoga Sūtra. This articulation of yoga became established as one of the six orthodox philosophies of Hinduism.

These sutras hold meaning for us when the perennial questions about what we are, what our existence is, whether it has any meaning at all, arise anew. The word sūtra means “thread”: we reach for that thread to navigate the abyss and reach for the deep, in search of our “complete” self. The very first word of these sūtras is “atha”, meaning “now”. It is a word that is also a symbol, something sacred, something pregnant with meaning: it was the now in which the Sage Patañjali delivered its message; it is the now in which I contact that teaching; it is the now of my readiness to be open and receptive to it – and when I am, that is yoga.

The Sage Patañjali defined yoga as “the stilling of the movement of thought in the mind” in order to “know the true self”. He had adopted an even more ancient philosophy that held that while the idea-of “I”, the socially constructed self, was a mirage – behind it, masked by it, was an immanent and universal “self” worth the search. Yoga is a means whereby that search is made.

In the centuries that followed, yoga became the sap nourishing the mighty tree of Hinduism, flowing into every branch of its rich philosophy while always remaining rooted in the Vedas. From the 18th century onwards, as India was colonised, yoga travelled to Europe and academics took to translating its many texts into their own languages.

Then, in 1893, at the Parliament of the World’s Religions in Chicago, a fiery, saffron-clad Hindu monk, Swami Vivekananda, stood up and began his brief speech with the address: “Brothers and sisters of America … ”, bringing the audience to its feet for a two-minute standing ovation. Vedic philosophy had burst upon the west, bringing yoga with it – and we embraced it. Yoga is now ubiquitous. It appeals because it offers us a means to deal with ancient questions that cannot be suppressed.

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What is yoga? Despite its global travel, it remains all that we do to still the mind in order to know the true and universal self. So, is the well-toned figure sweating it out on the yoga mat doing yoga? Yes, by using the body the yogi trains the attention to handle the perennial questions. But the person walking their dog beside the river and contemplating the truth behind self, life and death, is also doing yoga. The beauty of yoga is that it meets us wherever we are and then invites us to continue the exploration – like young Nachiketas, the seeker in the Katha Upanishad, questioning even death.

My own yoga teacher, a Himalayan monk called Swami Venkatesananda, said: “Yoga is all those practices that enable us to discover health – which is not the absence of the symptoms of sickness, but which is wholeness and holiness, an inner state of being in which there is no division at all.”