Not only are their presence and power self-manifested, but they also shed a strong and clear light around them.

In this light, other truths are visible.
Luminaries themselves, it is their office to enlighten.

To their authority, in every department of thought, the sane mind bows promptly, gratefully, fully.

And by their authority, he explains, proves, and disposes of whatever engages his attention and engrosses his powers as a reasonable and reasoning creature.

For what, when thus employed and when most successful, is the utmost he can accomplish?
Why, to make the conclusions which he would establish and commend, _clear in the light of reason_;--in other words, to evince that _they are reasonable_.