Munch's The Scream rivals even the Mona Lisa Its creator, the Norwegian painter Edvard Munch is generally thought of as one of the most intensely serious of artists. But when it came to understanding the commercial potential of what he had created, he was no fool. Munch created four versions of "The Scream," one of which, a pastel from 1895, went under the hammer at Sotheby's in New York last night, selling for $119.9m (£73.9m), becoming the most expensive artwork ever sold at auction. Born in 1863, and 36 when he painted the first version of "The Scream," Munch is widely believed to have suffered from bipolar disorder. Writing of the painting's creation in his journal he described walking with two friends by the waterside in Oslo, and the sky turning "red as blood." He stopped, feeling "unspeakably tired. Tongues of fire and blood stretched over the bluish black fjord. My friends went on walking, while I lagged behind shivering with fear. Then I heard the enormous, infinite scream of nature. While it has been argued, with slight plausibility, that Munch was seeing red dust thrown up by the volcanic eruption at Krakatoa, this is more or less irrelevant to our understanding of the painting. What he shows us is how something that might normally be considered beautiful and reassuring, a sunset, can become the agent of overwhelming dread. This sense of anguish isn't localised to the sufferer, the strange, hairless figure in the bottom centre, but vibrates through every inch of the painting. The swirling lines of the land and water are infected by the mental miasma radiating from the sky, while the straight lines of the pier, with two ominous figures approaching from the rear are oppressive in their very rigidity. The central figure with its hands raised to its startled light bulb of a face may have been inspired by a Peruvian mummy exhibited in the 1889 Paris Exhibition, as has been widely claimed, but it is anonymity of this figure - with no discernible sex, age or ethnicity - that gives the painting its universality. Rather than showing us an individual, Munch shows us what we feel like in moments of isolation and mental agony. At the time of the painting's first unveiling, when depression was poorly understood, when mental illness was considered a shameful sign of weakness and people generally were discouraged from thinking about their selves, "The Scream" would have been seen as at best distasteful. But now, after a century of the ever-increasing influence of Freud and his followers, when "getting in touch with our feelings" is simply what we do, the figure in "The Scream" has become a kind of Everyman. Rather than seeing him as a pitiable wretch, we think "I've been there," or if not quite, then that we almost certainly will be at some point in our lives. The person who has never come close to the degree of extremity depicted in "The Scream" is, we tend to feel, a rather superficial and spiritually impoverished human being.