How solid is the evidence?

It's virtually impossible to prove whether apes are conscious, since neuroscientists still can't agree on how to define consciousness, or how it arises in the human brain. But advocates for ape rights say the fundamental question is not scientific, but moral. We do know for certain that great apes have complex mental abilities, which elevate their capability for suffering. On that basis alone, say rights advocates, apes deserve basic protections from the pain, isolation, and arbitrary imprisonment inflicted by medical experiments or captivity in zoos. "Great apes are thinking, self-aware beings with rich emotional lives," said Peter Singer. "If we regard human rights as something possessed by all human beings, no matter how limited their intellectual or emotional capacities may be, how can we deny similar rights to great apes?"

lai bu ji wen yin xing cun zhe de mi ma 
　　zhang da ye zui jin bei cha chu you xin zang bing 。
　　zai zhu yuan qi jian ，ta fa xian zi ji zai shui jue shi ，
　　lao ban ai bu shi yong shou zai zi ji de bi zi chu shi tan 。
　　shi jian chang liao ，zhang da ye hen bu kai xin ，
　　you yi ci ，ta gu yi ping zhu qi ，xiang kan kan lao ban jiu jing you shi me fan ying 。
　　chen mo liao ji miao zhong hou ，

　　zhi ting lao ban 喃喃zi yu dao ：“huai shi liao ，lai bu ji wen yin xing cun zhe de mi ma liao ！