Full Idea
It is in the Platonic philosophy that dialectic first occurs in a form which is freely scientific, and hence also objective. With Socrates, dialectical thinking still has a predominantly subjective shape, consistent with his irony.
Gist of Idea
Socratic dialectic is subjective, but Plato made it freely scientific and objective
Source
Georg W.F.Hegel (Logic (Encyclopedia I) [1817], §81 Add1)
Book Reference
Hegel,Georg W.F.: 'The Hegel Reader', ed/tr. Houlgate,Stephen [Blackwell 1998], p.171
A Reaction
I don't understand how dialectic can be 'objective', given that it is a method rather than a belief. Plato certainly seems to elevate dialectic into something almost mystical, because of what is said to be within its power.