"Human beings are the only animals of which I am thoroughly and cravenly afraid"

George Bernard Shaw's quote speaks to the distinct power of human beings and the worry they can stimulate. People are the only species capable of complex thought and interaction, and this enables them to produce and manipulate their environment in ways that no other animal can. This power can be used for excellent or ill, and it is this potential for harm that Shaw hesitates of. He acknowledges that human beings have the capacity to trigger immense suffering and destruction, and this is what he fears. He is likewise most likely describing the fact that humans are capable of ruthlessness and violence towards other animals, something that other animals are not efficient in. Shaw's quote is a suggestion of the immense power of humans and the responsibility we need to use it wisely.