This paper outlines how we may understand knowing-that as a kind of knowing-how-to, and thereby as an ability. (Contrast this form of analysis with the more commonly attempted reduction, of knowing-how-to to knowing-that.) The sort of ability in question has much potential complexity. In general, questioning can, but need not, be part of this complexity. However, questioning is always an element in the complexity that is philosophical knowing. The paper comments on the nature of this particular form of knowing.