That seems to satisfy him completely, but it can satisfy no other intelligent person. He leaves that word unexplained. Apparently he wants to shift the responsibility to our religious teachers. At the most he has made but the vaguest gesture towards a reply. Mores means manners and customs.
Morality is the conduct of life.
It is what we do with our social lives. It is how we deal with ourselves in relation to our fellow creatures. We are coming to see more and more plainly that certain established traditions which have made up the frame of human relationships for ages are not merely no longer as convenient as they were, but are positively injurious and dangerous. And yet at present we do not know how to shake off these traditions, these habits of social behaviour which rule us. The standard of living may not have been as high as our present standards, but the social stability and assurance were greater.