FOR some, of course, the answer is simple — to fulfil God’s purpose.

That answer itself comes in a variety of different guises — from the obligation to honour God (as if an omnipotent being requires the obsequies of lesser beings that s/he created) to perhaps more virtuous or creditable purposes — living honestly, frugally and virtuously; doing unto others as you would be done by, and so on.

It is perhaps a feature of our species that, unlike other species, we “need” a purpose, individually or collectively, beyond mere existence.

Marx called religion “the opium of the people” by which he didn’t (only) mean that the drug was fed to or forced onto people (although certainly, that’s often the case), but rather that people often sought a higher purpose, consolation or succour for their own physical or mental suffering: “The sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions.”

For others, not least those who profess a “scientific” understanding of these questions, the purpose of life for humans is no different from that of other species; survival and reproduction.

Certainly, survival and reproduction are drives common to all animal species including ourselves. (NB, not “instincts” — instincts are innate genetically determined behaviour patterns in response to particular stimuli and humans, interestingly, have very few of them but that’s a topic for another column).

Even here we have a problem: many social animals feature behaviour whereby individuals may prejudice their own survival and reproductive chances to the benefit of others of their species — something known as “group selection.”

An example often given is the blackbird alarm call. Faced with a potential predator, the alarm call may alert other blackbirds to danger, though the bird giving it may make itself more vulnerable as a consequence.

Some biologists assert that evolution operates only at an individual level and that what looks like altruistic behaviour is actually “pseudo altruism” — the closer social animals live together, the more likely they are to be related — to share their own genes; so in helping other animals to survive, although it may die in the process, our blackbird is actually increasing the chances of its own genes propagating.

In this view, humans are innately selfish, acquisitive and competitive, at least in regard to those who don’t share their genes, and who don’t belong to their family or “race.”

Marxist biologist Steven Rose calls these explanations “Just-So Stories’ because they lack evidence; they are put forward because they can sound convincing, and provide a convenient justification for whatever we want them to mean.

Ironically the “just-so” stories of genetic determinants of our nature and purpose meet with the “God gave me this” of evangelical religion.

If you’re not successful it’s because you’ve sinned or not tried hard enough; if you are, the riches you’ve received are God’s reward for obeying “his” commands.

In fact, Darwin himself — who never rejected the possibility of group selection — never had such a mechanical, reductionist view of the purpose of life, accrediting “higher” animals at least, with emotions (he even wrote a book about them) and a degree of consciousness.

Guides to purpose are everywhere, from newspaper agony aunt columns to social media and Sunday sermons. “Purpose” occupies the deliberations of philosophers as well as pundits. And they are always full of contradictions and circularity.

One popular version of “how we should live” is utilitarianism; seeking the greatest good for the greatest number, but this approach has difficulty defining what “good” is or how it can be measured.

The most popular version (philosophers call it “hedonistic utilitarianism”) defines it as “happiness.” And as earlier Full Marx columns — on alienation, reification and fetishism (number 51) and hegemony (number 82) argued capitalism has a remarkable knack for commodifying, of monetising your “purposes” for profit.

But ideas and values do not exist in a vacuum. As Engels declared: “The great basic question of all philosophy is that concerning the relation of thinking and being.”

A discussion of “purpose” implies something more than an attribution of blind compliance to some external or internal law, whether that be “God’s will” or a biological drive.

It implies a degree at least of self-conscious will; a higher motivation than mere survival and reproduction, higher even than the values of truth, justice, and humanity, which most socialists share with many others, whether or not they profess a “faith.”

For Marxists, it has to do with the way that Marx, Engels and an earlier Full Marx column (number 91) argued “human nature” is not fixed, it has changed — and will continue to do so — throughout history, in relation to the dynamics of society at any given point in time.

Throughout history, individuals have felt that things were “not right,” that life could be better, not just for themselves or their families, but for society as a whole.

And throughout history, where groups of people have felt similarly, they have challenged the status quo, sometimes trying to transform social relations into something different.

Clerkenwell Green, where Marx House stands today, has been the site of protest from the peasants’ revolt of 1381 to the annual May 1 rallies today. The French revolution of 1789-99 and the Russian revolution of 1917 are perhaps the best-known examples of major revolutionary activity involving individuals whose political commitment gave a purpose to others.

A recent presentation at Marx House (available online) argued that Jesus himself was a revolutionary — “a fervent and deadly serious religious organiser whose social and religious movement offered not only a radical end-time edict of divine reversal and judgment but also a promising new world order ruled in the interests of the peasantry.”

One often-quoted purpose, variously attributed to VI Lenin and Jawaharlal Nehru but in reality from Nikolai Ostrovsky, a Ukrainian writer best known for his novel How the Steel Was Tempered is: “The dearest possession of any person is life. It is given only once, and it must not be lived only to feel tortured by regrets for wasted years or to know the burning shame of a mean and petty past; so live that when dying you have a right to say: all my life, all my strength was given to the finest cause in the world — the fight for the liberation of humankind.”

Few of us can aspire to such total commitment — we have to earn our living, bring up our kids and socialise with our neighbours: but this isn’t a bad summary of revolutionary purpose. And it is one which, at particular junctures, has led many socialists, Marxists and others to make considerable sacrifices, not least at times of war.

So, to answer the question “what is the purpose of life” — it’s what we choose. That’s one of the things which make humans different.

Cecil Day Lewis’s poem The Volunteer was written for those who joined the International Brigades to fight in Spain. It applies equally to all those from any country who willingly take up arms and put their lives at risk to fight against fascism and for a better world:

It was not fraud or foolishness,
Glory, revenge, or pay:
We came because our open eyes
Could see no other way.

That motivation is one which guides most socialists, not only Marxists, in their — perhaps sometimes seemingly mundane — political activities. They do it because their “open eyes can see no other way.”

And that’s not a bad way to live.

Or to take a couplet from the 1970s progressive rock band If (no Marxists) we all need life, love, liberty — and at least some prospect, however small, of leaving a legacy: “I want it said when I am gone, I moved the world just one step on.”

This Saturday July 1 at 1pm in Jubilee Gardens on London's South Bank is the International Brigade Memorial Trust’s annual commemoration of the 2,500 men and women from Britain and Ireland who volunteered to fight fascism during the Spanish civil war of 1936-39. More details at international-brigades.org.uk.

The Marx Memorial Library’s rich programme of events and courses continues on Thursday July 6 with an online symposium Commemorating British Labour History: Foundations and Future Plans, examining the role of Marx Memorial Library at 90, the South Wales Miners’ Library at 50 and the Modern Records Centre at 50. Details and past Full Marx columns are on marx-memorial-library.org.uk.