Allow yourself to mentally revisit the specific situation. Then question the concept in writing, using the following questions and turnarounds. When answering the questions, close your eyes, be still, and witness what appears to you.
Example of a statement: Paul lied to me.
Possible opposites: I lied to me. I lied to Paul. Paul didn't lie to me.
Contemplate how each turnaround is as true or truer in that situation.