John Wesley’s famous account of his heart being “strangely warmed” is often considered a conversion. However, his change is less about identity as a Christian, and is more about manner of being. Wesley’s change is best understood as an affective encounter. It is affective in being about bodily experience and initially pre-rational. However, that affective moment was possible due to previous encounters and intentional designs that prepared the possibilities for affective experiences. It is an encounter, following Louis Althusser’s theorization of the term, as a moment of change that might not have happened. Chance is taken seriously with the encounter, and combined with intentional design. Wesley might not have interacted with the Moravian sect in ways that set him up for his affective experience; rhetorical studies can use the encounter and affect to consider probability and chance more, and to think about rhetoric as the design of possible encounters.