Having two sides to an argument makes us realize that there are no ties in an argument. You either agree with the claim, or you disagree with the claim. But where do you start? You either stick with the status quo, the current situation, or you change to the new position suggested by the claim.
The theory of argumentation suggests you start against the claim until the pro-side can make a good and sufficient argument for you to accept the claim. The idea is that your current situation has gone along okay up until now. Why change and accept this new position? It is the burden of the pro-side to convince you of the claim being made. You always hear that in a criminal trial a person is innocent until proven guilty. The jury starts with the status quo of innocence and the pro-side, prosecutor, has to convince them to change their initial position and find the person on trial guilty.
If at the end of the argument you are still unsure if you either agree or disagree with the claim, you should reject the claim and not feel bad about it. Remember, there are no ties in an argument. Since pro-side was not convincing enough to convince you to accept the Claim, you resort back to your original “comfortable” position of the status quo. Clever sales people, however, attempt to use a tactic called Reversing the Burdens to manipulate you.