In his The Tragic Sense of Life, Miguel de Unamuno identifies consciousness as the perception of suffering. He writes:

And how do we know that we exist if we do not suffer, little or much? How can we turn upon ourselves, acquire reflective consciousness, save by suffering?

This observation turns Descartes’ “Cogito ergo sum” (I think therefore I am) into the existential “I suffer, therefore I am.”

Unamuno’s sentiment (at this point though later he addresses more) does not quite appreciate the fact that animals suffer and are undoubtedly conscious of their suffering, however we want to define it. I have suggested elsewhere that perhaps less animate beings may be conscious of their suffering, albeit impossible for humans to perceive. That we cannot perceive something, of course, does not mean that it does not exist. In this case, our very lack of perception is a grave ethical warning that we ought not to tread into opting for human against any other definition of consciousness or perception.

Unamuno goes on:

When we enjoy ourselves we forget ourselves, forget that we exist; we pass over into another, an alien being, we alienate ourselves. And we become centered in ourselves again, we return to ourselves, only by suffering.

Thus to be other than human is to not suffer. Yet we are but human and are inhuman if we do not acknowledge suffering. This return to self is not of itself an enlightenment. Sorrow and suffering override the positive aspects of consciousness in this scheme. Even creativity as a form of transcendence can fall so short that it becomes a vanity. Unamuno quotes Herodotus: “The bitterest sorrow that one can know is to aspire to do much and to achieve nothing.” Part of the lesson (not palatable to Western thought) is to not aspire to do much, a philosophy of life exemplified by Eastern culture, where action is not necessarily a form of creativity. Death in the end, as a goal to the trajectory of suffering, makes even the grandest of achievements into nothing.

This whole conversation ought to remind us of the Buddha’s first noble truth: all is suffering. Indeed, consciousness of this truth becomes the equivalent of Unamuno’s awareness of suffering, and both would conclude that this consciousness is what makes for being human.

Unamuno evens moves from knowledge (of suffering) to what is translated as pity but is more fully understood as compassion.

It is our reservoir of pity, eager to diffuse itself over everything, that makes us discover the likeness of things within ourselves, the common bond that unites us with everything in suffering.

Here is the convergence, using separate language and experience, of Western and Eastern perception, for the Buddha, too, sees the discovery of being in everything to form a bond and identity. From this experience can arise an ethic and philosophy of life, leaving aside as less urgent a metaphysics. The Buddha often taught (as in the parable of the poisoned arrow told to Malunkyaputta) that metaphysics could not be the first priority or motivation but rather the addressing of suffering and the implementation of a solution to suffering was the priority. Addressing suffering lies not in metaphysics but in the the mechanics of daily life and consciousness — in this case the Eightfold Noble Path.

The growth of consciousness in an individual is first an intensification of the awareness of suffering. It is a form of knowledge and suffering in itself, with a decidedly ethical component if the truths sought are genuinely reflective of reality and not projections of ego. But secondly, or in the second stage, consciousness is the emptying of ego in the intensification of that ethical component, which eventually becomes compassion, coupled with a strong will and ascetic component. Hence the paradox highlighted by historian Gavin Flood: the necessity to build a strong ego and will in order to understand, but also in order to renounce.