What is the criterion for a valid doubt in matters of shirk (associating partners with Allah)?

Question:
What is the criterion for a valid doubt and an invalid doubt?

Answer:
The subtle matter that may be hidden is clarified by the thing that may be hidden; for example, if someone thinks that asking the absent one is not shirk (associating partners with Allah), it is said to him: The absent one is of two types:
If you ask the absent one by writing or by telephone, it is not shirk (associating partners with Allah).
And if you ask while believing that he hears your words while he is absent, and that he benefits you: this is the major shirk (associating partners with Allah) that the polytheists did with the angels and with their objects of worship other than Allah.