How we change what others think, feel, believe and do
When talking with others, a part of our speech can be in defending.
A natural use of defending is to provide support for an argument we make, pre-emptively finding ways to defuse the challenges others might to what we have proposed. This may be done by gradually building up the case and then making the proposition, or alternatively stating what we believe and then adding reasons for doing so afterwards.
If we do not add justifications to argument (and perhaps even if we do) then others may argue against us, just stating us as wrong or criticizing our reasoning. When this happens, we usually leap to defend what we have said, and the attack-defend pattern can continue for some time. If we feel that the attack is personal, then we will switch from defending the argument to defending our selves. In doing so, we may easily become emotional and irrational.
We should go out today because we haven't been out recently and I want to get a few things.
Leave her alone! That was an unnecessary personal attack.
Yes, I know it's irrational, but I want to do it.
A person may have elements of their personality that leads to defending, for example where they have a poor self-image and consequentfeelings of inadequacy. It may also be based on a desire to be and appear rational, which leads to careful explanation of what is being said and the rationale behind it.
When we defend, we may do so with carefully reasoned logic, but often we use weak argument and fallacies. We may also use simple assertions of belief or emotional statements that can have elements of coercion in them, effectively saying 'If you disagree, then you will be a bad person for upsetting me, which will then justify my attacking you in return.' In this way, defending can become attacking, which forces the other person to defend.
Attacking the person is a common method of distraction as it causes the other person to move from promoting or defending their argument to defending their ego. As this becomes more emotional, the original argument may be forgotten, which may well be the primary intent of the attacker.