‘West Coast Black art stands in direct opposition to art for art’s sake. It insists that if art is not for the sake of something it is not art.’

This quote, from the American artist Noah Purifoy, is to be found in Tate Modern’s exhibition Soul of a Nation. Art in the Age of Black Power, and raises questions that, overtly or otherwise, are central to all artistic endeavour: Why am I doing this? What purpose, if any, does it serve?

Throughout most of history such agonising would have been thought pointless, even heretical. Art was not a separate category but embedded in social or religious life, the artist a craftsman who knew his or her place. The cave painters of Lascaux were admired no doubt but served an ecstatic vision that was collective in nature and possibly drug-induced. However exalted, Imhotep the pyramid-builder worshipped as well as obeyed his god-king. And Phidias, great sculptor of Zeus, immortalised deities or perfection in human form, both subjects inherently ideological. The architects of Europe’s Gothic cathedrals were billed as masons, where they are known at all, the glory they strived for not personal but royal and divine. In Bali, an island as saturated with images as anywhere on earth, artists only began to sign paintings in the 1930s, when visiting westerners taught them to monetise their work. And so on.

So where did it come from, the notion of art as a subjective activity, sufficient unto itself? Talent would always have had its due, pushing boundaries and attracting reward: a place near the fire, first dibs on the slave girls, one’s mark on the chancel wall. By the time of the Renaissance artists as celebrities were well-established, albeit deferential to prince or Church. Then, as capitalism developed, new patrons and subjects came into play, Dutch masters like Vermeer becoming fascinated by the landscape, exterior and domestic, of their new, mercantile world. In Britain, birthplace of industrialism, art became a commodity available to an emerging middle class which, keen to imitate aristocratic taste, was a soft touch for artists and dealers; while developments in printing enabled the wholesale reproduction of images, which hung as engravings on ever-more humble walls.

Thus the grip of ideology and patronage was slackening as the artist’s options increased. Still great voices were raised in defence of art as secondary to values – Ruskin’s high-mindedness stands out, as does Nietzsche’s insistence that art cannot avoid strengthening or weakening current hegemonies of thought. But the contrary view had begun to be theorised, by Whistler among others, and with Turner’s work light, hitherto the medium through which some prescribed reality was depicted, became a subject in itself, just as physics was supplanting religion as the key to understanding the universe. Art developed a momentum of its own, with movements and fashions driven by practitioners’ experiments with style, the market struggling to keep up, chequebook in hand. It helped to have Gaugin, Van Gogh & co perpetuating the image of the doomed genius, one’s tortured soul established as the proper concern of art; but mostly they were becoming cannier at milking the punters, Picasso’s signed napkins to the fore.

Art for art’s sake became a slogan, a watchword for integrity and the human spirit. What was this: an aberration, or a new, liberating stage in human development like access to education and cheap travel? Accountability still had strong advocates, backed up by armies and secret police. Socialist realism was Stalin’s riposte to artistic freedom: heroic labour, hummable tunes. And now we have Islamists destroying temples in Syria and threatening libraries in Timbuktu. Yet is the culture that evolved from artistic freedom any less shallow or beholden? Today’s market panders to the super-rich. Paintings sell for hundreds of millions. Boardrooms outbid galleries in a war of the walls. ‘Art for art’s sake,’ sang 10cc, ‘Money for God’s sake’. Meanwhile style and subject matter have never been further removed from the understanding of most people, at a time of pressing global issues like poverty and climate change. Can we afford such self-indulgence? Is this the result of allowing artists a free hand?

Which brings us back to the Tate exhibition, Black Power and Noah Purifoy. His statement, quoted at the beginning, can now be seen as historically more representative than the opposite, supposedly prevailing point of view. What would we have thought of a black artist choosing that moment to explore the quality of light in Mississippi, as cities burned and bodies dangled from trees? Yet Purifoy’s own response was far from what Stalin meant by art relevant to the people. No images here of the oppressed, nobly struggling. Instead, he made his mark with sculptures formed from wreckage left behind by the 1965 Watts rebellion (called riots by the media: how we name things is also contested, politicised). In other words, even if we expect art to be ‘for the sake of something’, the form that engagement takes is open to interpretation, with gifted, creative minds able to lead, rather than follow opinion. And that is what we find in the rest of the exhibition. Just as the civil rights movement and Black Panthers enacted contrasting strategies of resistance to oppression, so the artistic community differed in its creative response. Those working with abstraction were criticised for being too rarefied or introspective, but insisted they were articulating a no-less distinctive voice. Others, while being more accessible, also focused on developing a black aesthetic as a means of dignifying their community rather than portraying its immediate troubles, the photographs of Roy Decarava being a case in point. And in America the Beautiful Norman Lewis could dare to make an arresting image out of Klan members gathering in the night, its appeal not only moral but aesthetic as well.

I left the Tate troubled by Purifoy’s polemic but here is one way the circle might be squared: expect art to address some form of meaning external to itself but defend with your life the freedom to choose how this is done.