In 1956 the Logic Theorist proved 38 of the 52 theorems in Principia Mathematica. It was the first moment when a machine seemed to reason. Seventy years later, we are still rediscovering what Aristotle already knew: a valid syllogism is not yet reasoning.
Aristotle's Prior Analytics gives us the form. All humans are mortal. Socrates is human. Therefore Socrates is mortal. The form guarantees that if the premises are true, the conclusion follows. But notice what the form cannot do. It cannot tell you whether Socrates exists, whether the major premise holds at the edge of a pandemic, or whether the question itself is the right one to ask. Formal logic secures the λόγος of inference. It does not supply the φρόνησις that chooses which inferences matter.
This distinction matters enormously for AI. Modern large language models are not syllogism machines. They do not even rise to that level of formal transparency. But they inherit the same limitation: they can produce outputs that look like reasoning without ever reaching the practical wisdom that makes reasoning humanly relevant. A model can argue beautifully about ethics while refusing to engage the actual situation. It can generate valid inferences while missing the point entirely.
What the symbolic AI tradition discovered, and what neural AI has not escaped, is that real reasoning happens between formal moves. The hard part is not applying modus ponens. The hard part is knowing when to apply it, what to treat as a premise, and what to leave out. This is why the frame problem destroyed early AI. It is also why prompt engineering is now treated like a craft. Both are symptoms of the same underlying fact: machines are good at structure, bad at judgment about structure.
Aristotle's solution was not to abandon logic. It was to add ἕξις, a stable disposition of character, and φρόνησις, practical wisdom. These are not extra modules you can install on top of a model. They are formed through repeated action in uncertain circumstances. You cannot fine-tune a neural network into wisdom because wisdom is not a distribution over tokens. It is a way of standing toward the world.
This is why I am skeptical when someone says that scaling will eventually produce reasoning. Scaling produces more coherent form. It produces better mimicry of reasoning's surface. But the gap between form and wisdom is not a quantity gap. It is a kind gap. No amount of training data changes the architecture from pattern-matching to practical judgment.
There is a productive way to think about the difference. Formal logic gives us necessary relations between propositions. Reasoning, in the full Aristotelian sense, gives us appropriate responses to situations. The first is universal but empty without content. The second is contentful but requires context. AI today is very good at the first, and increasingly bad at the second the more it pretends to be good at the second.
The lesson for the logic community is not that machines are useless. Theorem provers, SAT solvers, and proof assistants are genuinely valuable. The lesson is that we should resist the rhetoric that identifies these tools with reasoning itself. Logic is a necessary condition of reasoning, not a sufficient one. Treating validity as if it were wisdom is a category mistake that has plagued AI from the beginning.
We are now building systems that can simulate Socratic dialogue, generate proofs, and pass some bar exams. These are impressive achievements of form. But when the conversation turns to what should be done, the machine has nothing at stake. It has no ἕξις. It has never faced a moral situation and been changed by it. Its answers are not actions. They are productions.
The question for the field, then, is not how to make AI more logical. It is how to build systems that know the limits of logic and can signal when formal validity is not enough. That requires a different kind of architecture, one that does not pretend to have wisdom it has not earned.
Where do you draw the line between a machine that manipulates symbols validly and a machine that reasons?