Plato, Aristotle, Kant, and Hegel all give reason an ethical mission that goes far beyond what formal logic can do. Formal logic has immense value in specialized contexts like the engineering of systems, but does not necessarily or directly yield any philosophical insight. As Aristotle said, it is a tool and not an independent source of knowledge.

As Paul Ricoeur has pointed out, a wide variety of such technical tools can also indirectly serve to sharpen a hermeneutic understanding. But for that to be possible, a hermeneutic project must already be underway.

Nevertheless I would argue that for Plato, Aristotle, Kant, and Hegel among others, such a project is precisely what “reason” primarily amounts to. More than anything else, reason is constituted by reflective interpretive judgment. Only secondarily is it concerned to deduce consequences from premises. Every such deduction either implicitly presupposes reflective interpretive judgments about meaning, or simply assumes that meanings are already somehow pre-given.

But reason at its core is the ramified and expansive understanding of meaning, as well as the process of aiming at and achieving such understanding, and the putting of that understanding into practice. And “reasonableness” is a matter of an emotional constitution that allows judgments to be made without bias or prejudice or excessive self-centeredness, so that one’s actions reflect and manifest this kind of understanding.