Truth stages

 "Truth passes through three stages.  First, it is ridiculed.  Second, it is violently opposed.  Third, it is accepted as being self-evident." -- Arthur Schopenhauer

Doors of Perception

 "If the doors of perception were cleansed every thing would appear to man as it is, infinite. For man has closed himself up, till he sees all things thro' narrow chinks of his cavern." -- William Blake, The Marriage of Heaven and Hell.

Don't try to be subtle or clever

 "If you have an important point to make, don't try to be subtle or clever.  Use a pile driver.  Hit it once.  Then come back and hit it again." -- Winston Churchill