Will yourself to only be able to see through someone's eyes (perceive what that person is perceiving) only if a proposition is true. You can do the same but choose to see only if the proposition is false.
Choose the subject providing the eyes or perception you are sensing to be someone unconnected to the proposition subject matter.
It is like an If-Then statement in computing eg. If (something is true) Then (see what other person is looking at).
This technique has many implications and is an infinitely valuable gift.
It means that you cannot be lied to. But one must be aware of the context and be smart. It may be that someone or some group will try to fool you. They can do this if their telepathy is supported by more people than yourself or your group. Therefore one should try asking questions around the proposition, measure what can be observed in reality, and do every other thing to ensure that one is not being fooled.
If an opposition group has greater number and is working to misdirect your telepathy than they can fool you. But they cannot fool you all of the time because it is impossible to disguise or misdirect all questions (all questions being telepathic and what reality shows).
It is probably best to test both the truth and then the falsity of a proposition in two separate tests.