In an earlier period this might have been a religious painting, instead of an ''orrery'' (which is an invention of about 1710, designed to illustrate the movement of the planets round the sun). These rapt faces, with their intentness lit by a centre of strong light in a dark room, might have come to gaze at the newborn child in a manger; or they might have been disciples breaking bread with Jesus on the road to Emmaus, the fact of resurrection dawning slowly on their features.
Joseph Wright of Derby, in this fine picture from his early maturity (painted about 1764-66), translated the visual language of Dutch 17th-century painters into the terms of an original and up-to-date 18th-century subject. The light, which comes from a candle or lamp masked from the viewer by the boy with his back to us, serves as a source of wonder, increasing the expressiveness of features, dramatizing the search for knowledge, the realization of ideas, the intensity of thought preoccupying this selection of people learning about the patterns and configurations of the planets. For the purposes of the orrery itself, this light represents the sun. The way the surrounding faces are caught by it acts as a metaphor for the illumination of whatever is lit by the actual sun, so this intimate indoor scene is a microcosm which carries a universal significance, suggesting a scale much vaster than the immediate one. It is a measure of Wright's sense of the momentous, and his ability to make a painting dramatic, that he has been able to express something of the awe and admiration for nature and the universe felt by his contemporaries.
Scientific knowledge was being widely popularized at this period. The philosopher's audience here does not consist only of cognoscenti; it is surely meant to represent a cross section of ordinary men, women and children. Particularly charming are the two children with their faces brightly lit, framed by the armillary ribs of the orrery, fascinated by this curious construction and its ingenious motions: this was a kind of primitive planetarium, operated by turning a handle.
There is a theory that the model Wright used for the lecturer, the white-haired gentleman who dominates the scene, was John Whitehurst, a maker of clocks and scientific instruments who, like the painter, lived in Derby and was a friend. His face was described later in life as both ''penetrating'' and ''mild,'' which fits the philosopher of the picture well.
Whitehurst is known to have advised Wright on his paintings of scientific subjects (for which the painter demanded of himself the most detailed accuracy), and it seems likely that Whitehurst's intellectual curiosity and technological inventiveness were a stimulus to the painter's ideas. These pictures of scientific genre scenes were not commissioned, as were Wright's successful portraits. So they can be seen as evidence of the artist's most personal interests, and those of his friends.
About a decade after he produced ''the orrery,'' Wright was in Italy witnessing an eruption of Vesuvius. He wrote home to his brother: ''When you see Whitehurst, tell him I wished for his company when on Mount Vesuvius; his thoughts would have center'd in the bowels of the mountain, mine skimmed on the surface only; . . .'' Here we have the appreciation of the visual artist, only too aware of the limitations of his art, for the thinking, analytical scientist.
Wright made a number of Vesuvius paintings after his experience in Naples. To him, the painter, it was ''the most wonderful sight in nature.'' But he obviously felt that for his friend Whitehurst, who was working at the time on a geological treatise called ''Inquiry Into the Original State and Formation of the Earth,'' it would have had a meaning deeper than spectacular appearance. A painter, by contrast, could only skim the surface.
However, it was this vivid appreciation for the enquiring, probing attitudes of science which Wright had, in fact, so marvellously and ambitiously conveyed in his ''Philosopher Giving a Lecture on the Orrery.'' It owed a debt, no doubt, to Rembrandt's pictures of meditating scholars, those wise old men of his, and even perhaps to the famous Dr. Tulp giving his anatomy lesson. The great Dutch painter's ability to suggest unfathomable wells of thought and experience, often enigmatically hidden in the shadowy foreheads of figures themselves almost lost in obscure rooms redolent of things musty, ancient and academic, must have appealed to the painter of ''the orrery.''
Whatever its art-historical precedents, though, in its own totality it is startlingly original. Its most obvious feature may be the effect of light, but this is by no means pursued just for its own sake. Much more is contained in this work than simply a ''wonderful sight.'' It is a profoundly stilled and highly dignified tribute to the excitement of intelligence -- of large, even universal, notions being eagerly grasped and weightily pondered.