One person investigating the experience of another can be directly aware only of his own experience of the other. He cannot have direct awareness of the other’s experience of the ‘same’ world. He cannot see through the other’s eyes and cannot hear through the other’s ears. The only true voyage, Proust once remarked, would be not to travel through a hundred different lands with the same pair of eyes, but to see the same land through a hundred different pairs of eyes. All one ‘feels’, ‘senses’, ‘intuits’, etc. of the other entails inference from one’s own experience of the other to the other’s experience of one’s self. This presupposes that the other’s actions are in some way a function of the other’s experience, as I know mine to be. Only on the basis of this presupposition, however qualified it may be, can one hazard inferences about the other’s experience from one’s perspective of the other’s actions.

R. D. Laing, "Self and Others" 14
Guy Mackinnon-Little