وَكَانَ مَرْجِعُ الْكُلِّ إِلَى الْعَقْلِ
All of these were ultimately referred back to reason.
Another account treats imagination, experience, intuition and similar mental acts as modes of rational operation rather than additional independent basic sources. Reason has a central role in connecting meanings and forming judgments.
Repeated observation provides material, while deriving a general principle requires inference. Thus sensation and reason may contribute to the same conclusion.
Calling reason foundational does not entail that no sensory experience can occur without an explicit syllogism. The issue concerns classification of epistemic sources and cognitive operations.