The German philosopher and classicist Karl-Martin Dietz emphasizes the original term of dialogue, which goes back to Heraclitus: "The logos [...] answers to the question of the world as a whole and how everything in it is connected. Logos is the one principle at work, that gives order to the manifold in the world."  For Dietz dialogue (gr. dia-logos) means "a kind of thinking, acting and speaking, which the logos "passes through""  Therefore, talking to each other is merely one part of "dialogue". Acting dialogically means directing someone's attention to another one and to reality at the same time. 
Ernest, I can see possible issues with the example you mentioned, about moving back and forth between characters and then having multiple paragraphs of dialogue from a single character. Yet most readers will see the closing quotation mark or the lack of it. I’m certain you’d end up creating more problems if you were to have a closing quotation mark in one paragraph and an opening quotation mark in the next paragraph if the two paragraphs contain the words of a single speaker. That is, the instances when a reader doesn’t note the absence of a closing quotation mark will be fewer than the instances when readers do note the presence of a closing quotation mark where it’s not supposed to be.
Socrates then returns to the myth of the chariot. The charioteer is filled with warmth and desire as he gazes into the eyes of the one he loves. The good horse is controlled by its sense of shame, but the bad horse, overcome with desire, does everything it can to go up to the boy and suggest to it the pleasures of sex . The bad horse eventually wears out its charioteer and partner, and drags them towards the boy; yet when the charioteer looks into the boy's face, his memory is carried back to the sight of the forms of beauty and self-control he had with the gods, and pulls back violently on the reins. As this occurs over and over, the bad horse eventually becomes obedient and finally dies of fright when seeing the boy's face, allowing the lover's soul to follow the boy in reverence and awe. [Note 33]