To people doubting whether the ape "understood," the language, a useful test is whether it used language as a) a tool to operate on its environment through othe

To people doubting whether the ape "understood," the language, a useful test is whether it used language as a) a tool to operate on its environment through others, and b) to realize individually originated intent. There is another criteria for basic intelligence whether the subject is capable of reasoning about objects that are not physically present. A dog scratching at a door to signal its desire that it wants you to open it, is arguably using language. Responding to commands is not necessarily using or understanding language as it can just be explained as being acted upon. I'm sure there is a philosophical catgory for this interpretation, of language as tool, but it has a lot of ethical consequences.