Final answer:
Rationalization is the defense mechanism described in the question where a person justifies their thoughts or behaviors to avoid the truth.
Step-by-step explanation:
The defense mechanism described in the question is rationalization.
Rationalization is a defense mechanism where a person justifies their thoughts or behaviors by substituting acceptable reasons for less-acceptable real reasons. It involves creating excuses or explanations that make their actions seem reasonable or acceptable, even if they are not.
For example, someone who is trying to avoid the truth may rationalize their actions by making excuses such as 'I had a really busy day and couldn't find the time' or 'It wasn't a big deal anyway'.