Religious texts, philosophy, ethics, and even self-improvement books often don't provide a procedure to follow. They teach things like how to handle conflict, how to act fairly, how to navigate difficult situations, or how to reason about competing values.
People then take those ideas and apply them across many different situations in their daily lives. In a sense, they build a toolbox of reusable mental functions rather than memorizing a single algorithm.
That's also why many people finish a self-improvement book feeling like they didn't get much out of it. They were expecting a recipe. Instead, they absorbed a collection of abstractions that only reveal their value when applied later in real situations.
The fact that cookbooks are imperative mainly shows that procedural tasks are naturally expressed procedurally. It's not obvious that this generalizes to human reasoning as a whole.