Method 1
Using two-way identification
of information of positive
and negative nature
Specifically, when the ancients received a certain piece of information, they would endeavor to find another source of information that was related to that information but had an opposite position or contradictory content. For example, in the military, political or economic fields, if they heard a certain party claiming a major victory or discovering new resources, they would try to obtain relevant information from the enemy or neutral party to verify the authenticity of this information. This kind of comparison of positive and negative information is like the two ends of a scale, where the content, credibility and logical reasoning of the information on both sides are weighed to determine which side is closer to the truth.