Generations of malleable Israeli children are brought up on story of misnamed Jewish settlement Tel-Hai ("Mount of Life"), Israel's Alamo. There, among picturesque valleys of Galilee, a one-armed hero named Joseph Trumpeldor is said to have died, eight decades ago, from an Arab stray bullet, mumbling: "It is good to die for our country." Judaism is dubbed "A Teaching of Life" - but it would seem that sanctity of life can and does take a back seat to some overriding values.

The right to life - at least of human beings - is a rarely questioned fundamental moral principle. In Western cultures, it is assumed to be inalienable and indivisible (i.e., monolithic). Yet, it is neither. Even if we accept axiomatic - and therefore arbitrary - source of this right, we are still faced with intractable dilemmas. All said, right to life may be nothing more than a cultural construct, dependent on social mores, historical contexts, and exegetic systems.

Rights - whether moral or legal - impose obligations or duties on third parties towards right-holder. One has a right AGAINST other people and thus can prescribe to them certain obligatory behaviours and proscribe certain acts or omissions. Rights and duties are two sides of same Janus-like ethical coin.

This duality confuses people. They often erroneously identify rights with their attendant duties or obligations, with morally decent, or even with morally permissible. One's rights inform other people how they MUST behave towards one - not how they SHOULD or OUGHT to act morally. Moral behaviour is not dependent on existence of a right. Obligations are.

To complicate matters further, many apparently simple and straightforward rights are amalgams of more basic moral or legal principles. To treat such rights as unities is to mistreat them.

Take right to life. It is a compendium of no less than eight distinct rights: right to be brought to life, right to be born, right to have one's life maintained, right not to be killed, right to have one's life saved, right to save one's life (wrongly reduced to right to self-defence), right to terminate one's life, and right to have one's life terminated.

None of these rights is self-evident, or unambiguous, or universal, or immutable, or automatically applicable. It is safe to say, therefore, that these rights are not primary as hitherto believed - but derivative.

The Right to be Brought to Life

In most moral systems - including all major religions and Western legal methodologies - it is life that gives rise to rights. The dead have rights only because of existence of living. Where there is no life - there are no rights. Stones have no rights (though many animists would find this statement abhorrent).

Hence vitriolic debate about cloning which involves denuding an unfertilized egg of its nucleus. Is there life in an egg or a sperm cell?

We are human because we are not animal, nor machine. But such thinking has been rendered progressively less tenable by advent of evolutionary and neo-evolutionary theories which postulate a continuum in nature between animals and Man.

Our uniqueness is partly quantitative and partly qualitative. Many animals are capable of cognitively manipulating symbols and using tools. Few are as adept at it as we are. These are easily quantifiable differences - two of many.

Qualitative differences are a lot more difficult to substantiate. In absence of privileged access to animal mind, we cannot and don't know if animals feel guilt, for instance. Do animals love? Do they have a concept of sin? What about object permanence, meaning, reasoning, self-awareness, critical thinking? Individuality? Emotions? Empathy? Is artificial intelligence (AI) an oxymoron? A machine that passes Turing Test may well be described as "human". But is it really? And if it is not - why isn't it?

Literature is full of stories of monsters - Frankenstein, Golem - and androids or anthropoids. Their behaviour is more "humane" than humans around them. This, perhaps, is what really sets humans apart: their behavioural unpredictability. It is yielded by interaction between Mankind's underlying immutable genetically-determined nature - and Man's kaleidoscopically changing environments.

The Constructivists even claim that Human Nature is a mere cultural artefact. Sociobiologists, on other hand, are determinists. They believe that human nature - being inevitable and inexorable outcome of our bestial ancestry - cannot be subject of moral judgment.

An improved Turing Test would look for baffling and erratic patterns of misbehaviour to identify humans. Pico della Mirandola wrote in "Oration on Dignity of Man" that Man was born without a form and can mould and transform - actually, create - himself at will. Existence precedes essence, said Existentialists centuries later.

The one defining human characteristic may be our awareness of our mortality. The automatically triggered, "fight or flight", battle for survival is common to all living things (and to appropriately programmed machines). Not so catalytic effects of imminent death. These are uniquely human. The appreciation of fleeting translates into aesthetics, uniqueness of our ephemeral life breeds morality, and scarcity of time gives rise to ambition and creativity.

In an infinite life, everything materializes at one time or another, so concept of choice is spurious. The realization of our finiteness forces us to choose among alternatives. This act of selection is predicated upon existence of "free will". Animals and machines are thought to be devoid of choice, slaves to their genetic or human programming.

Yet, all these answers to question: "What does it mean to be human" - are lacking.

The set of attributes we designate as human is subject to profound alteration. Drugs, neuroscience, introspection, and experience all cause irreversible changes in these traits and characteristics. The accumulation of these changes can lead, in principle, to emergence of new properties, or to abolition of old ones.