After purgatory was officially defined by the Catholic Church in the thirteenth century, its location became a topic of heated debate and philosophical speculation: Was purgatory located on the earth, or within it? Were its fires real or figurative?

Diana Walsh Pasulka offers a groundbreaking historical exploration of spatial and material concepts of purgatory, beginning with scholastic theologians William of Auvergne and Thomas Aquinas, who wrote about the location of purgatory and questioned whether its torments were physical or solely spiritual. In the same period, writers of devotional literature located purgatory within the earth, near hell, and even in Ireland. In the early modern era, a counter-movement of theologians downplayed purgatory's spatial dimensions, preferring to depict it in abstract terms—a view strengthened during the French Enlightenment, when references to purgatory as a terrestrial location or a place of real fire were ridiculed by anti-Catholic polemicists and discouraged by the Church.

The debate surrounding purgatory's materiality has never ended: even today members of post-millennial ''purgatory apostolates'' maintain that purgatory is an actual, physical place. Heaven Can Wait provides crucial insight into the theological problem of purgatory's materiality (or lack thereof) over the past seven hundred years.