Logic
Hegel (complete work)
Not formal logic (rules of inference), but the science of pure determinations of thought. Logic develops the categories with which we think --- not as subjective forms, but as structures of reality itself.
Origin
Aristotle: organon (tool of thought). Kant: transcendental logic (conditions of possibility). Hegel: speculative logic (self-development of the concept).
In Hegel
Enc. §19-244; SL (complete work)