Systematic study of valid reasoning arose more than once, in places with little or no contact. The results overlap substantially but differ in ways that reflect what each tradition wanted logic for.
The Greek route began with argument in public
Greek logical writing developed alongside a culture of public dispute in courts and assemblies, where an argument had to persuade listeners who could judge it.
The early formal work concentrates on the structure of inference, classifying the forms a valid argument can take and separating them from forms that merely look valid.
This produced a strongly syntactic approach, in which validity depends on the shape of the argument rather than on its subject matter, and that abstraction became the tradition's most exportable feature.
Indian logic grew from rules of debate
Indian schools developed their analysis inside formal debate between philosophical positions, where the conditions for defeating an opponent had to be agreed in advance.
Their treatments give unusual weight to the grounds of an inference, asking what makes one thing a reliable sign of another and cataloguing the ways such a sign can fail.
Perception, inference and testimony are treated as distinct sources of knowledge with distinct rules, which gives the tradition a more explicitly epistemological character than early Greek work.
Chinese work focused on names and distinctions
Classical Chinese philosophical writing approached related problems through language, asking how names correspond to things and what happens when a term is applied inconsistently.
Debates about the correct use of terms carried political weight, since administration depended on categories being applied the same way by different officials.
The resulting literature is concerned with disambiguation and correct classification rather than with formal inference patterns, which is a genuinely different emphasis rather than a less developed one.
The traditions met and influenced each other
Transmission across regions happened repeatedly through translation movements, and Buddhist logical writing in particular carried Indian methods into East Asia over several centuries.
Translation forced clarification. Rendering a technical term into a language without an equivalent obliged translators to state what the term had meant, and those explanations survive.
Later scholars in several regions worked with more than one tradition at once, and their comparisons are among the earliest examples of deliberately comparative philosophy.
Comparison shows what logic inherits from its setting
The overlap between traditions is substantial, which suggests that some results follow from reasoning itself rather than from any culture.
The divergences track purpose closely. A tradition built for courtroom persuasion, one built for scholastic debate and one built for administrative clarity emphasise different questions.
Modern formal logic draws on all of them unevenly, and historians of the subject continue to recover material from the non-European traditions that earlier surveys omitted.