I just picked up Heidegger's Being and Time last week, and I just started reading it last night. I'm not very far in, but already I've got a question about his work. In the opening pages of the book, as he sets up the premise for the need to requestion the meaning of being, he states that an inquiry involves 3 entities; the entity doing the inquiring, the entity answering the inquiry and the entity being inquired about. Certainly this is true in a normal sense, I ask Tom about Mary, 3 entities are involved. If I ask Tom about Tom, obviously only 2 entities are involved, Tom and myself. The point is that this is not the case in all inquiries, some inquiries may have only 1 entity involved, if I ask myself what my birthday is, I am the enquirer, the enquiree and the subject of the inquiry.

In my mind, however, in a philosophical sense, the inquirer and the inquiree must always be one and the same. Heidegger does not specifically state it, but I believe it can be assumed, that when we discuss an inquiry, especially a successful inquiry, which is what he was treating with, it must be an inquiry that results in a truthful answer. Without digging into exactly what we mean by truthful, which could be a book in and of itself, let us say that by truthful we mean what would commonly be understood to be truthful. I cannot know the truthfulness of an answer given by another entity unless I prove it to myself. I may take an answer provided by another as truth as a matter of convenience, but I may not know it as a truthful answer unless I take the time to verify it's truthfulness on my own.

If someone were to tell me that 2+2=4, that may be a truthful statement, but until I evalutate it myself, it's veracity remains undetermined in my mind. So an inquiry, if it must be truthful, must be an inquiry of self; otherwise the truthfulness of the inquiry cannot be evaluated. I could inquire of another, but such answers as I might receive would later have to be evaluated; evaluation, if we consider it, must be concluded to be an inquiry of self about an entity.

Thus in a philosophical inquiry, if our goal is to get a truthful answer to our inquiry, the asker and the answerer must be one and the same, negating the need to deliniate 3 entities involved in the inquiry and removing the possible complication of erroneously naming a 3rd entity in our inquiry; in truth there can only be 2.

Am I missing something? Is there an instance in which a 3rd entity is involved in a philosophical inquiry?