One often hears that this or that action is justified or unjustified morally on the grounds that it is 'natural' or 'unnatural'. To say that something is 'natural' is really just to say that this is how things happen to be. Yet just because something happens to be the case, it doesn't mean that it ought to be the case. After all, there are plenty of things in life that are natural – for instance illness and disease, droughts and earthquakes; even emotions such as aggression, jealousy, anger and a desire for revenge. This does not mean that they are to be encouraged or welcomed. To say of something that it is natural, or unnatural, is not to provide anything by way of moral justification.