Man has a desire to know the truth because he guides his life by this knowledge. Now, truth is the conformity between the mind and reality which may be visible, invisible or both.
The human mind is limited and inclined to explore reality from different view points or mind sets, thus we have scientists, psychologist, philosopher, politicians and theologians. The higher the perspective, the more inclusive it becomes. For example, a physicist sees man composed of atoms and energy fields; the biologist sees man as an interactive organism; the philosopher is more concerned with man's origin, nature and end while the theologian sees man from the point of view of God's revelation as the image of God with a destiny in God's creative plan.
The human mind search for truth is subject to error because it may try to interpret the whole of a particular reality only from one perspective and is also vitiated by a lack of understanding motivated by pride. So there are limits to reasoned understanding of truth, but truth is being itself which is much richer than our understanding of it.
Only God the Creator has complete and absolute knowledge of Himself and each created reality with all its inter relationships and purposes but by light of reason and God's Revelation we can know the truth by which to guide our lives.
So, when human beings as individuals or groups are unable to determine what is true they turn to authority.