Similarly, I can look you straight in the eye and tell you that I feel fine, while I am in fact suffering great pain internally. Does this mean that I am not in

Similarly, I can look you straight in the eye and tell you that I feel fine, while I am in fact suffering great pain internally. Does this mean that I am not in pain? How could you know? You can't. There is no reason for an animal to dissimulate in this way, so we may as well accept their outward expression of pain or pleasure at face value.