The deep and the simple: feeling the way

''The biggest urge was to bust up the sophistication all around me,'' Ben Nicholson said of his youth. This urge seems to have continued ever since. Instead of following or developing any art theories, he returned to a fundamental desire to draw and paint with whatever came to hand as simply as he could - as a cave man or primitive would have done - out of his own experience and being.

''A painting is made in order to realise an idea and it can only exist in its own right as an experience of living on the part of the painter and when a new piece of reality is revealed in this way, it becomes overnight a part of general experience,'' he wrote later. For him, painting and religious experience were the same thing, a search for ''the understanding and realisation of infinity,'' as he put it, ''giving to all things for all time.''

He must always have had some such intimations, but he put in a lot of work before he made those statements and even more before he exemplified them as well as in ''Ticino Maggiore''(1981). In his nearly ninety years he moved from very simple drawing and painting to sculptural abstraction to combinations of both, always with a classic, serene sense of proportion and balance, but slowly feeling his way along. Feeling is the key word.

His feeling of form - of hill, mug, architecture - with all of the senses, plus the feeling for indoor and outdoor space, and for the tangible as well as the metaphorical, moves the hand over the paper. It is important, too, that he always lived close to nature, maintaining contact with that basic reality. Long experience of drawing as well as of walking over hills, handling mugs, moving through buildings, enables him to relate one to another in visual poetry.

Commenting on such readiness, he said, ''In some moods one cannot put a foot right and in others not a foot wrong. These line drawings of mine are made with great ease and after years of experience I know the signs of when I can make them and when I can't. It is not the drawing that is difficult but finding and recognising the mood. When in this right mood one knows well that something will come.''

Many artists would agree, but few stick to such simplicity. Along with the years of experience one needs a childlikeness that allows ever fresh perception and receptivity and ensures continued growth. Ben Nicholson observed that one needed always to think of himself as a young artist who might one day achieve something.

Through the years he seemed to find and express more and more of the mental nature of the universe. ''Colour,'' he said, ''exists not as applied paint but as the inner core of an idea and this idea cannot be touched physically any more than one can touch the blue of a summer sky.'' In ''Ticino Maggiore'' there are two areas of roof-tile red (shown in this reproduction as dark gray geometric shapes on the right) which convey such an idea.

In his sculptural reliefs he managed to give a painted equivalent of the inherent nature of wood or stone, land, sea or sky. He also got to the point where he took the familiar forms of objects in a still life and played with the volumes and lines to indicate an essence rather than a material thing.

During a visit to Dieppe, France, he got an insight into spatial awareness by noticing what happened in the window of a shop with the fairy-tale name ''Au Chat Botte'' (Puss in Boots). The name set up an abstract frame of reference for him. The lettering on the glass served to define one plane; the reflections of the life behind him in the street defined another; and the objects on a table inside the window represented a third plane. Nicholson described these objects as ''performing a kind of ballet and forming the 'eye' or life-point of the painting (which he subsequently produced). . . . These three planes and all their subsidiary planes were interchangeable so that you could not tell which was real and which unreal, what was reflected and what unreflected, and this created, as I see it now, some kind of space or an imaginative world in which one could live.''

This is what he has created so skillfully in ''Ticino Maggiore.'' In it we have an inner and an outer world simply and harmoniously interconnected. Obviously it was produced in one of those ''right moods.''