Siddhartha Gautama -- the Buddha -- had a much grander ambition than simply coaching his followers to avoid mental anguish. He wanted to teach them how to be released from the torturous cycle of rebirth -- the hell of reliving the suffering of aging, sickness and death, over and over again. He counseled that suffering in this and future lives is a product of desire (attaching to earthly pursuits), which arises from ignorance (misunderstanding reality). By meditating on the fleeting quality of our perceptions, he was convinced we could penetrate the true nature of reality and ourselves (i.e., discover that existence is characterized by impermanence, suffering and "no-self"). Meditation paves the way for enlightenment by facilitating the key epiphany of "knowing suffering": a fleeting, impermanent world can neither satisfy our desires nor offer us sustained happiness; in fact, attaching ourselves to impermanent things is precisely the cause of our suffering. Desire is both misplaced (because it is based on the illusion that we are separate selves whose wants can be satisfied) and destructive (because it locks us into a permanent cycle of suffering lives). Once our illusions are corrected, we realize how misplaced our desires are and immediately renounce all earthly pleasures and pursuits -- all of them, including love, friendship, family, fine food, personal goals (other than enlightenment) and anything that represents an attachment to anything of any kind. In turn, our suffering is curtailed and rebirth into future lives of suffering is halted.
The Buddha's teachings were passed down orally for 400 years before they were written down in 29 BCE. They were transmitted as discourses that were memorized by his followers (which is why many of his recorded sermons begin with "This is what I heard..."). Gautama insisted that upon his death nobody should take his position as "chief teacher" (he preferred a power-sharing governance among his disciples). As a result, his followers splintered into many factions, giving rise to several interpretations and doctrinal variations by generations of monks who recounted and translated his ideas. We don't have access to his actual words, but there is academic consensus that many (not all) of his 3,000 recorded sermons (suttas) are likely authentic.
Gautama claimed that he did not create the Four Noble Truths (the centerpiece of his philosophy) but that he rediscovered this crucial but forgotten ancient wisdom: i) Life entails suffering; ii) Desire is the cause of suffering; iii) Cessation of suffering is possible; iv) The key to permanent cessation is the eight-fold path to enlightenment (right view, right intention, right speech, etc.). Meditation is the vehicle through which we discover and embrace these four truths -- the only metaphysical truths available to us -- which are not simply insights, but prescriptions for being.
Was the Buddha's message unique?
It's difficult to pinpoint what his unique philosophical contribution was to Eastern thought, beyond the themes he inherited from 6th century BCE Hindu thinking, which formed the basis of his ideas. There is no way of knowing which of his ideas were added to or tweaked by the many followers who interpreted his words and eventually recorded them centuries after his death. He is sometimes erroneously credited as being the first meditator: meditative practice dates back to the pre-Hindu yogic traditions that likely arose from the rituals of ancient Shamanism. Gautama absorbed philosophies from a number of monks with whom he studied and while each of these monks developed a unique yogic practice, they all shared a common belief that desire was the culprit of human suffering and desire stems from misunderstanding reality. The yogic tradition of the time was directed towards eliminating ignorance and quelling desire through concentrative practices that facilitated access to the eternal and unchangeable "Self" that resides within each person. Gautama challenged this prevailing philosophy of cosmic Self; his alternative view is considered by many scholars to be original.
He argued that "self" is nothing more than a bundle of shifting sensations, thoughts and feelings - changing states of existence that arise and vanish as part of the fluid and contingent nature of reality of which we are all a fundamental part. It is the illusion of a separate, immutable identity that contributes to the suffering we endure as we seek to satisfy the desires of this illusory self. Buddha argued that there is no permanent soul, neither within us nor within the universe. There is merely a flickering energy, like a flame that jumps from one wick (life) to another, unless it is deprived of fuel (desire and attachment). Unlike his contemporaries, he did not consider enlightenment to be based on the unification of individual self with universal Self; Gautama's version of enlightenment was based on a profound epiphany about the nature of ourselves as part of a fluctuating, impermanent whole.
In addition to "no self" (anatta), a second element of the Buddha's philosophy that was likely outside of the mainstream yogic tradition was his emphasis on attentive self-scrutiny. Whereas the concentrative focus of meditation had traditionally been on a very narrow field of sensation (typically the breath, but sometimes other bodily sensations), Gautama advocated for both this narrow concentration as well as a focus on all mental activity occurring in the moment. The breath was a starting point for expanding awareness to all sensations and ultimately to the busy comings and goings of thoughts and feelings. It is by turning our mental spotlight onto our thinking that we can become aware of how transient, chaotic and pointless our ever-churning machinations are, how illusory our sense of self is, and therefore how futile our attempt to satisfy desire is. For Gautama, the power of mindfulness (sati) depends on awareness of the full spectrum of our experience; otherwise, we cannot understand our true nature and escape suffering.
Aside from "no self" and his broad perspective of mindful attentiveness, most of Gautama's core ideas were derivative. But it was not the uniqueness of his message that preserved his teachings for over two millennia. It was how he articulated and championed certain concepts in a compelling and charismatic way that led to a large contingent of devoted followers who diligently spread his gospel. Whether these ideas are useful today is a separate question - one that is addressed in Part II.