A warm body in a box The late Donald Judd's minimalism can seem impersonal, even ascetic. Not so, sa ys Brydon Smith

I first met Donald Judd in the late Sixties but I'd already seen his work in 1965. It was just so different from anything else. So much so that it took me a couple of years to really understand it. It was his retrospective at the Whitney in 1967

that was the epiphany for me.

This show in Oxford gives the full range of Don's work. It's a beautifully installed selection, ranging from prints and furniture to large objects. There are woodcuts, which might surprise some people, but they suit Don. When you make a woodcut you're removing part of the block - in a sense removing the space. In this, and upstairs in the three floor-related pieces, you find the real importance of Judd. He was the artist who defined and informed values of space. Henry Moore and others had explored having holes move through an object - and through space - but it was Don who really made space one of the primary media.

In the upper galleries, one room has been devoted to a single large work. It's very serene. It's comprised of seven plywood boxes measuring 78in x 78in x 78in, made from one and a half inch thick plywood sheets. It's structurally very solid. The boxes a r e open front and back and run the full length of the gallery with intervals of 1ft between each and a 1ft gap at the end walls. It completely transforms the space into an experience you have to to move into and through.

Next door is a room with cadmium-red light - a favourite of Don's - it's so saturated. And next to that is another large room with one of his "stacks": stainless steel boxes attached to the wall with red plexiglass top and bottom. The red light diffuses into the spaces between the boxes. These objects in particular define Don's sensibility, which is that of a painter. He started off as a painter and never lost the joy of colour.

One of the important aspects of Don's art for me is the distinct separation of the parts. There's no hierarchical relationship involved. He has an incredibly fine sense of proportion. I always feel "comfortable" with Don's work. Even his very large workshave a human scale. They're never intimidating. Don was a humanist. His works are not cold and dry and formal.

People might accuse him of that, but if they would only slow down and allow themselves to experience it, and not come here with preconceived notions, then they would understand.

n Brydon Smith is the curator of 20th-century art at the National Gallery of Canada, Ottowa. He is the author of the definitive 1975 catalogue raisonee of Judd's work. He was talking to Iain Gale n Donald Judd's work is at the Museum of Modern Art, Oxford (08165 722733) to 26 March. For details, see listings below