Here's an incomplete list of ancient books which failed to make the cut.
The Gospel of Thomas
The Gospel of Philip
The Gospel of Peter
The Gospel of Nicodemus (also called the "Acts of Pilate")
The Gospel of Bartholomew
You don't believe in them, and neither do I. So I ask again: who determined the Canon? And on what basis?
God did, on the basis of which writtings He had inspired.
Could the Church put Thomas in the Canon? Why or why not? If it does, would Thomas gain in authority, or would it always have had this authority?