Being able to perceive others as fellow subjects has been referred to as having a theory of mind or being able to assume the intentional stance, and these terms emphasise the secondary nature of this capability. It is not built-in in a generally unproblematic way like stereoscopic depth perception but in common with other kinds of theory it is built up in stages and passes through a number of cognitive turning points which are not universally assured. The questions of the degree to which it is more a theory than a practical skill - riding a bicycle is not the same as having a theory of velocipedality - and of what is its relation to empathy - overlapping or orthogonal? - aside, it is a matter of certain functional beliefs which are acquired through experience and which only alter, apart from the effects of disease or trauma, in the direction of becoming more comprehensive and inclusive. The perception of others grows like a theory, and is even sometimes seen as a late acquisition connected to the ability to appreciate realist art. In the novels of George Eliot, for example, we are shown the growth of this capacity as a creative leap prompted by suffering and other checks to the ego. Some of the stages here include going from perceiving others' intentions toward us - or those which directly affect us - to others' intentions toward third-persons and toward themselves; and expanding the view from the intentions of others to their thoughts and feelings; and from seeing their actions as expressions of their selves to seeing them as expressions of their understanding, indeed of the current state of their own theories. These theories must be in good part a cultural product and so anxiety about failures in theory building must always be present, expressed perhaps in fantasies of zombies, AIs and serial killers, but generally projected safely away from the self. There are other functional theories that we build in the process of humanisation which would appear to be built on top of a theory of mind and to therefore be posterior and more abstract, but since these include the self more fully their fractures and anxieties are prone to raise far more intense passions. In particular these posterior syntheses include the theory of good life, that of intimate relations and that of the social network.