represent visual translations of verbal metaphors and puns drawn from both biblical and folkloric sources. However, the conflict of interpretations that his works still elicit raises profound questions about the nature of "ambiguity" in art of his period. Latterly art historians have added a further dimension to the subject of ambiguity in Bosch's work, emphasising ironic tendencies, for example in The Garden of Earthly Delights, both in the central panel (delights), and the right panel (hell). They theorise that the irony offers the option of detachment, both from the real world and from the painted fantasy world, thus appealing to both conservative and progressive viewers. According to Joseph Koerner, some of the cryptic qualities of the artist's work are due to his special focus on social, political, and spiritual enemies, whose symbolism is, by nature, obscure because it is intended to conceal or to harm. A 2012 study on Bosch's paintings alleges that they actually conceal a strong nationalist consciousness, censuring the foreign imperial government of the Burgundian Netherlands, especially Maximilian Habsburg. By systematically superimposing images and concepts, the study asserts that Bosch also made his expiatory self-punishment, for he was accepting well-paid commissions from the Habsburgs and their deputies, and therefore betraying the memory of Charles the Bold. Debates on attribution The exact number of Bosch's surviving works has been a subject of considerable debate. His signature can be seen on only seven of his surviving paintings, and there is uncertainty whether all the paintings once ascribed to him were actually from his hand. It is known that from the early 16th century onwards numerous copies and variations of his paintings began to circulate. In addition, his style was highly influential, and was widely imitated by his numerous followers. Over the years, scholars have attributed to him fewer and fewer of the works once thought to be his. This is partly a result of technological advances such as infrared reflectography, which enable researchers to examine a painting's underdrawing. Art historians of the early and mid-20th century, such as Tolnay and Baldass, identified between thirty and fifty paintings that they believed to be by Bosch's hand. A later monograph by Gerd Unverfehrt (1980) attributed twenty-five paintings and 14 drawings to him. In early 2016, The Temptation of St. Anthony, a small panel in the Nelson-Atkins Museum of Art in Kansas City, Missouri, long attributed to the workshop of Hieronymus Bosch,