The conviction of truth of some statement or reality of some phenomenon especially on examination of evidence. (religion.blogs.cnn.com)
This kind of consideration has even led some philosophers to urge the acceptance of scientific claims where acceptance involves no belief about the truth or probable truth of the statement itself. (religion-online.org)
Gerald H. Jacobs and Jeremy Nathans reveal the literal truth of that statement in «The Evolution of Primate Color Vision». (scientificamerican.com)