Famous historian of Fascism Zeev Sternhell has identified personalism with fascism in a very controversial manner, claiming that Mounier's personalism movement "shared ideas and political reflexes with fascism". He argued that Mounier's "revolt against individualism and materialism" would have led him to share the ideology of fascism.
Personalism flourished in the early 20th century at Boston University in a movement known as Boston Personalism and led by theologian Borden Parker Bowne. Bowne emphasized the person as the fundamental category for explaining reality and asserted that only persons are real. He stood in opposition to certain forms of materialism which would describe persons as mere particles of matter. For example, against the argument that persons are insignificant specks of dust in the vast universe, Bowne would say that it is impossible for the entire universe to exist apart from a person to experience it. Ontologically speaking, the person is “larger” than the universe because the universe is but one small aspect of the person who experiences it. Personalism affirms the existence of the soul. Most personalists assert that God is real and that God is a person (or as in Christian trinitarianism, three persons, although it is important to note that the meaning of the word 'person' in this context is significantly different from Bowne's usage).
Bowne also held that persons have value (see axiology, value theory, and ethics). In declaring the absolute value of personhood, he stood firmly against certain forms of philosophical naturalism (including the social Darwinism of Herbert Spencer) which sought to reduce the value of persons. He also stood against certain forms of positivism which sought to reduce the importance of God.
Philosopher Immanuel Kant, though not formally considered a personalist, made an important contribution to the personalist cause by declaring that a person is not to be valued merely as a means to the ends of other people, but that he possesses dignity (an absolute inner worth) and is to be valued as an end in himself.
Martin Luther King, Jr. was greatly influenced by personalism in his studies at Boston University. King came to agree with the position that only personality is real. It solidified his understanding of God as a personal God. It also gave him a metaphysical basis for his belief that all human personality has dignity and worth. (see his essay “Pilgrimage to Nonviolence”)
Pope John Paul II was also influenced by personalism. Before becoming Pope, he wrote Person and Act (sometimes mistranslated as The Acting Person), a philosophical work suffused with Personalism (ISBN 90-277-0985-8). Though he remained well within the traditional stream of Catholic social and individual morality, his explanation of the origins of moral norms, as expressed in his encyclicals on economics and on sexual morality, for instance, was largely drawn from a Personalist perspective. His writings as Pope, of course, influenced a generation of Catholic theologians since who have taken up Personalist perspectives on the theology of the family and social order.