  Personalism exists in many different versions, and this makes it somewhat difficult to define as a philosophical and theological movement. Many philosophical schools have at their core one particular thinker or even one central work which serves as a canonical touchstone. Personalism is a more diffused and eclectic movement and has no such common reference point. It is, in point of fact, more proper to speak of many personalisms than one personalism. In 1947 Jacques Maritain could write that there are at least “a dozen personalist doctrines, which at times have nothing more in common than the word ‘person.’” Moreover, because of their emphasis on the subjectivity of the person, some of the more important exponents of personalism have not undertaken systematic treatises of their theories.