Paterson and Rand promoted each other's books and conducted an extensive correspondence over the years, in which they often touched on religion and philosophy. An atheist, Rand was critical of the deist Paterson's attempts to link capitalism with religion. Rand believed the two to be incompatible, and the two argued at length. Their correspondence ended after they quarreled in 1948. During a visit to Rand at her home in California, Paterson's remarks about writer Morrie Ryskind and abrasive behavior toward businessman William C. Mullendore, other guests of Rand, resulted in Rand's disillusionment with "Pat."