What is an intelligent spirit?

Will the controlling intelligence please tell us why spirits do not give their whole names when asked to do so while communicating through test mediums? They will give their first name, but seldom give the surname when if the whole name were given it would give much better satisfaction to sceptical people.

Spirits labour under a great many more disadvantages in returning to manifest here after death. When they return, they are suddenly ushered back again to the world―their medium is imperfect―they find their work very hard and they struggle to give even one word.

Names are hard to give―first, for this reason―when the sitter comes into rapport with the medium and the spirit who has a desire to possess the medium and to manifest through it, the sitter's first, most intense and most positive thought is the name of the party that is to control. If it were possible for the sitter to render his mind entirely passive to what might come, the manifestations would be far more reliable and names would come much easier.

―Theodore Parker in Spirit