overcoming biological limitations by drawing on futurology and various fields of ethics. Unlike many philosophers, social critics and activists who place a moral value on preservation of natural systems, transhumanists see the very concept of the specifically natural as problematically nebulous at best and an obstacle to progress at worst. In keeping with this, many prominent transhumanist advocates, such as Dan Agin, refer to transhumanism's critics, on the political right and left jointly, as "bioconservatives" or "bioluddites", the latter term alluding to the 19th century anti-industrialisation social movement that opposed the replacement of human manual labourers by machines. A belief of counter-transhumanism is that transhumanism can cause unfair human enhancement in many areas of life, but specifically on the social plane. This can be compared to steroid use, where athletes who use steroids in sports have an advantage over those who do not. The same scenario happens when people have certain neural implants that give them an advantage in the work place and in educational aspects. Additionally, there are many, according to M.J. McNamee and S.D. Edwards, who fear that the improvements afforded by a specific, privileged section of society will lead to a division of the human species into two different and distinct species. The idea of two human species, one being at a great physical and economic advantage in comparison with the other, is a troublesome one at best. One may be incapable of breeding with the other, and may by consequence of lower physical health and ability, be considered of a lower moral standing than the other. Nick Bostrom stated that transhumanism advocates for the wellbeing of all sentient beings, whether in non-human animals, extra-terrestrials or artificial forms of life. This view is reiterated by David Pearce, who advocates for the use of biotechnology to eradicate suffering in all sentient beings. Currents There is a variety of opinions within transhumanist thought. Many of the leading transhumanist thinkers hold views that are under constant revision and development. Some distinctive currents of transhumanism are identified and listed here in alphabetical order: Abolitionism, the concept of using biotechnology to eradicate suffering in all sentient beings. Democratic transhumanism, a political ideology synthesizing liberal democracy, social democracy, radical democracy and transhumanism. Equalism, a socioeconomic theory based upon the idea that emerging technologies will put an end to social stratification through even distribution of resources in the technological singularity era. Extropianism, an early