related issues arouse public controversy. Criticisms of transhumanism and its proposals take two main forms: those objecting to the likelihood of transhumanist goals being achieved (practical criticisms) and those objecting to the moral principles or worldview sustaining transhumanist proposals or underlying transhumanism itself (ethical criticisms). Critics and opponents often see transhumanists' goals as posing threats to human values. Some of the most widely known critiques of the transhumanist program are novels and fictional films. These works of art, despite presenting imagined worlds rather than philosophical analyses, are used as touchstones for some of the more formal arguments. Various arguments have been made to the effect that a society that adopts human enhancement technologies may come to resemble the dystopia depicted in the 1932 novel Brave New World by Aldous Huxley. On another front, some authors consider that humanity is already transhuman, because medical advances in recent centuries have significantly altered our species. However, it is not in a conscious and therefore transhumanistic way. From such perspective, transhumanism is perpetually aspirational: as new technologies become mainstream, the adoption of new yet-unadopted technologies becomes a new shifting goal. Feasibility In a 1992 book, sociologist Max Dublin pointed to many past failed predictions of technological progress and argued that modern futurist predictions would prove similarly inaccurate. He also objected to what he saw as scientism, fanaticism and nihilism by a few in advancing transhumanist causes. Dublin also said that historical parallels existed between Millenarian religions and Communist doctrines. Although generally sympathetic to transhumanism, public health professor Gregory Stock is skeptical of the technical feasibility and mass appeal of the cyborgization of humanity predicted by Raymond Kurzweil, Hans Moravec and Kevin Warwick. He said that, throughout the 21st century, many humans would find themselves deeply integrated into systems of machines, but would remain biological. Primary changes to their own form and character would arise not from cyberware, but from the direct manipulation of their genetics, metabolism and biochemistry. In her 1992 book Science as Salvation, philosopher Mary Midgley traces the notion of achieving immortality by transcendence of the material human body (echoed in the transhumanist tenet of mind uploading) to a group of male scientific thinkers of the early 20th century, including J. B. S. Haldane and members of his circle. She characterizes these ideas as "quasi-scientific dreams and prophesies" involving visions of escape from the body coupled with "self-indulgent, uncontrolled power-fantasies". Her argument