In his 1991 novel Mao II, Don DeLillo called the literary medium “a democratic shout”. His oft-quoted claim is that any man or woman on the street could strike it lucky, find their voice, and write a great book. Not only does everyone carry round a novel, but those novels are potentially brilliant. Well, it’s not a Pulitzer nomination but in Brighton right now, any ordinary Joe can walk in off the street and find their art put on the wall at the city’s foremost gallery.

Back in the early Sixties Lucian Freud was living in Clarendon Crescent, a condemned row of houses in Paddington which were gradually being demolished around him. The neighbourhood was uncompromisingly working class and to his glee his neighbours included characters from the seamier side of the criminal world.

Brett Goodroad (b. 1979) is an artist and painter based in San Francisco. Born and raised in rural Montana, in 2012 he received the Tournesol Award, overseen by Sausalito’s Headland Center for the Arts. The Award recognises one Bay Area painter each year and financially assisted Goodroad and gave him studio space, allowing him to develop his distinctive, figurative, abstract style.

I can’t pretend to like the work of Fahrelnissa Zeid, but she was clearly an exceptional woman and deserves to be honoured with a retrospective. She led a privileged life that spanned most of the 20th century; born in Istanbul in 1901 into a prominent Ottoman family, many of whom were involved in the arts, she died in 1991.

Standing inside the Gemeentemuseum’s life-size reconstruction of Mondrian’s Paris studio, the painter’s reputation as an austere recluse seems well-deserved.

Painted during his first trip to Paris in 1900, Picasso’s Le Moulin de la Galette is an outsider’s view of an exotic and intimidating new world. Men and women are seen as if through some strange distorting lens, their blurred, mask-like faces indistinct but for red-slit mouths and coal-black eyes. We seem to be in the room with them, and yet we are isolated. Even a woman looking out from the edge of the canvas gazes straight past us: if not invisible, we are certainly inconsequential.

Celebrating the four ages of man, eight huge, semi-abstract paintings create a carnival atmosphere in the Serpentine’s central gallery. The freshness of Childhood is characterised by flowers, petals and stamens floating on a blue ground. The passions of Youth warrant a ground of hot orange crammed with circles and spirals jostling for space like amoeba in a petrie dish. Adulthood is dominated by a large, yellow gourd-like shape on a lavender ground; dancing in attendance are looping letters and clover-leaf swirls.

From its title, you could be misled into dismissing this show as narrow and self-referential: a small exhibition in a small gallery curated by a Belgian artist concerned only with his own countrymen. In fact, it is something of a survey, featuring works with influences that range from Piet Mondrian, Ad Reinhardt and Lucio Fontana, to the Color Field painters.

One of the earliest surviving sculptures by Barbara Hepworth is a toad made from a khaki-coloured, translucent stone; you can imagine it cool and heavy in your hand, not so very different from the animal itself, in fact. Made nearly 30 years later, the monumental sculptures carved from African guarea wood are almost unbearably touchable, each one with its dark, glossy exterior cracked open to reveal an inside as creamy as a conker. But while we are denied the pleasure of touching these objects, looking at Hepworth’s work is in itself a gloriously tactile experience.

Light. Light banishes the shadows where monsters lurk and where ghosts rattle their chains. “Give me some light, away!” cries the usurping king in Hamlet as his murderous deed is exposed by the trickery of art. What guilt plagues and seizes his conscience, and yet Claudius, conflicted, cannot pray. He must, therefore, remain a captive among the ghosts and the monsters where no light may fall.