I had first met Caro just before the great Picasso: Sculptor/Painter show opened at the Tate four years ago. He was approaching his much celebrated 70th at the time and had already held the undisputed title of Britain's Leading Living Sculptor for some years.
His reputation was established back in the early Sixties when he revolutionised British sculpture, welding steel into brilliantly coloured abstractions, and dispensing with the customary plinth. The breakthrough came after a seminal trip to the States where he met the American sculptor, David Smith. "David taught me above anything to put my art first," says Caro. "I learned a lot from him".
Caro, white-bearded and elegant, is urbane, entertaining, and highly articulate. But lengthier conversation reveals both the rebel, who delighted in flouting convention, and the child, a slightly restless spirit, eager for new sensations.
I remember vividly his contagious excitement on the eve of the Picasso show. He was and still is up for new experiences and new stimulation for his art. Feelings of claustrophobia break out at the idea of being put in a box labelled Famous Artist. "I'm still compelled to keep on experimenting, following new paths even if some must fail," he says. "Otherwise, what's the point? Life would be quite intolerably dull".
On the eve of his show at the National Gallery, the first ever show of contemporary sculpture to be staged there, Caro professes to be both excited and nervous. "It's not as bad as it was in my younger days," he says. "Before my first show at the Whitechapel in 1963 I was almost physically sick with nerves."
Is he so drawn to Picasso because he was an artist who in his eighties still revelled in shock tactics? "Yes, of course I love Picasso because he never gave up the desire to challenge and provoke. That was the nature of the man. And it is what great art is about".
"I think that if it weren't for Picasso we'd all be very different artists", he says. "Picasso really cracked the egg and broke it open. Suddenly it was 20th-century art. Every artist had to pay attention because it was a different way of seeing. He utterly changed the future of sculpture in a way which was revolutionary and outrageous."
"He was quite clearly mad at certain stages, but he didn't have the terrible lack of certainty to say `Am I mad?'. Everything he did, he kept. If he did go down the wrong rails, they didn't block him. He was able to grow from those trails."
Caro is also hugely stimulated by the symbiotic relationship between Picasso the sculptor and Picasso the artist. Although he has rarely painted himself, Caro's work has been consistently inspired by the art of the past and often by painters of the past. "I remember being infuriated when I tried painting that I couldn't move a square of blue," he says with a laugh.
Caro's new pieces will be shown at the National Gallery in the context of the great masters who inspired them - Giotto, Rembrandt, Goya, Leonardo, Mantegna, Manet and Matisse.
He has also made a series of five new works inspired by Van Gogh's Chair, a work he finds inspirational for its structural qualities.
"When the Director, Neil MacGregor, first suggested that my work should be shown alongside Van Gogh, I almost panicked. I still feel very diffident about showing my work in the company of the greatest art. Yet there is another part of me which longs for the proximity of work that means so much to me. Van Gogh has been a hero since my early teens when I was miserable at school. I saw him then in an intensely romantic way after reading Lust For Life.
"But as you walk around the National Gallery, you see paintings by artists who had their own problems to work through. They were not settling down to paint a masterpiece, much less an Old Master. Exhibitions like this help to show that there is no real break in continuity between old figurative art and abstract art. In every period the artist has to find a way through to a visual truth that works for him in the time he lives."
Francis Bacon, who Caro has admired and whose show at the Hayward will run concurrently with his, often professed similar fascination with the Old Masters. "Why, after the great artists, do people ever try to do anything again?" he once gloomily remarked. Like Caro, indeed like Picasso, Bacon saw no contradiction in being an avant-garde, experimental artist whilst still looking back to the great art of the past. But does Caro feel it essential for all artists to look at the Old Masters? "Yes, I do. More and more," he says. "For one thing, your heroes don't stay the same. Mine change all the time. As a student I loved the romanticism of Romanesque art. Later I loved Donatello and then when I was working as Henry Moore's assistant, I started to use Etruscan figures as a starting point for my own figures".
He expressed reservations about the Sensation show at the Royal Academy last autumn, precisely because he felt few of the artists were engaging in any significant way with their roots. "A lot of the work was like sight bites, one look is enough. It's all too instant and too fast - like a Victorian melodrama. No wonder Charles Saatchi likes it, because it is like advertising. Rachel Whiteread was the big exception - head and shoulders above the rest." Caro is also suspicious of the current obsession with fame.
"People ask me `How do I get to be famous like Andy Warhol?' and I say `Better to try and be like Rembrandt!'. I've nothing against a bit of fame. Very good for the confidence. But it should never be the main objective.
"I think to be an artist it is important to be at least a little rebellious, questioning - non-conformist, if you like. I hated my school days at Charterhouse. I didn't fit in at all. Perhaps it was being Jewish. Maybe I wasn't good enough at games. I think I was also a bit dyslexic, but there was no help for that then. But the seeds of wanting to make my own way on my own terms were probably there."
"Being a sculptor is very different from being a painter. Perhaps less introspective. Being a sculptor tends to be more physical, so you often work with others. I'm constantly wanting the reaction of others. My wife [the painter, Sheila Girling] and I discuss our work endlessly".
Caro's father, a wealthy Jewish stockbroker, wanted his eldest son to do "a proper job", join the family firm and abandon what he viewed as dilettante aspirations to be an artist. Caro now believes he was partly driven to prove that being an artist is a proper job. (Sadly his father didn't live to see his success). Certainly he has been astonishingly productive. "I make sculpture almost every day. It's not a duty, it's my life".
Critics have suggested that Caro is entering a late style - a period of intense aesthetic invention, when an artist can pursue his own path, with less need to please regular patrons.
"I hope that the ability to grow and look again will always stay with me. I think that we are living in strange times in the Nineties and artists respond to that. Things often seem unsettled, impermanent - unhappy. Maybe once we've got over the millennium, people will be able to relax and start again. I look forward to that".
`Caro at the National Gallery: Sculpture from Painting', National Gallery, Trafalgar Square, London WC2 (0171-747 2885) to 4 May. Free admissionReuse content