The moral group is expanding. We can chart this expansion quite clearly over the past few hundred years. It has been non-linear, irregular and punctuated by some retrograde and lamentable aberrations. Nevertheless, the direction of travel is clear; while at one point the interests of a select few were elevated above all others, the moral group is now far more inclusive. Through a series of struggles, widespread acceptance of previously excluded individuals and groups has been achieved. Historically excluded groups are now firmly included in our collective moral considerations. Most recently, the moral group has expanded in such a way that non-human animals are at its margins and in some cases within its borders.