Damien Hirst fires back at critic, compares art to currency While the debate of art versus commerce has probably plagued creative types since shortly after someone first offered a steak in exchange for viewing a cave painting, such considerations aren't an issue once you reach the level of celebrated U.K. artist Damien Hirst. Known for such attention-grabbing works as a shark suspended in formaldehyde as well as high-profile collaborations with Blur and Eddie Izzard in the '90s, Hirst recently came under attack from critic Julian Spalding, who wrote a pointedly titled short book, "Con Art -- Why You Ought to Sell Your Damien Hirsts While You Can." In a piece reported Monday by Reuters, Hirst playfully fired back at Spalding, who described Hirst's works as "worthless financially." I think art's the greatest currency in the world. Gold, diamonds, art -- I think they are equal," Hirst countered while speaking to journalists outside the Tate Modern gallery, which is hosting a Hirst retrospective that opens this week. I think it's a great thing to invest in. Hirst added, "It's like, you say, 'Sell your Hirst.' I say, 'Don't sell your Hirsts, hang on to them.' Hirst then recommended consideration of recent numbers, which as of last week included an auction where Hirst's doodle of his famous shark fetched $7,500. The drawing was given to a chauffeur as a tip. Numbers, once again, don't lie. Damien Hirst to build 500 eco-homes Hirst's web site to feature live streaming art-making Photo: Damien Hirst poses in front of one of his pieces at the Tate Modern on Monday. Credit: Oli Scarff / Getty Images.