It is the Second Person to Speak Who Starts the Argument.
What do you call it when one person is speaking?
The voice of one person is usually a monologue, sermon, or lecture – not the start of an argument. Argument potential starts when a second person joins with dissenting thoughts or feelings. Every argument requires at least two participants. The first speaker cannot compel another to respond. Getting hung up on who "started it" is irrelevant.
For many people, having an argument (debate, fight, difference of opinion, conflict, or whatever you call it) is a negative or uncomfortable activity. But, dictionary aside, people have varying senses of when the emotionality or persistence of a conversation has worked up into an undesirable communication.
As an example, have you ever been surprised when someone said, "Stop arguing with me," and you didn't feel you were arguing or even realize a conflict had started? Your conviction or passion along with their sensitivity to the topic created an argumentative feeling for them, even if you didn't perceive it that way. It goes nowhere to insist you are not arguing. Your insistence itself feeds the feel of an argument.
Certain people avoid conversations for fear an argument will begin. Avoidance habits rarely contribute favorably to an intimate relationship. Problems cannot be resolved without conversation. Your relationship cannot advance to the next level without conflict resolution. You and your significant other(s) need to look at your conversational styles and together make necessary changes to work through arguments.
Throughout life and relationships, sometimes you need to be the second person entering the conversation and expressing yourself – and risking an argument. It's not always a bad thing. A well-expressed argument builds understanding.
Remember – starting arguments can lead to growth, while avoiding them leads to distance.