William John Henry Boetcker (1873–1962) was an American religious leader and influential public speaker.
Born in Hamburg, Germany, he was ordained a Presbyterian minister soon after his arrival in the United States as a young adult. The Rev. Boetcker was ordained in Brooklyn, New York.
He quickly gained attention as an eloquent motivational speaker, and is often regarded today as the forerunner of such contemporary "success coaches" as Anthony Robbins.
An outspoken political conservative, Rev. Boetcker is perhaps best remembered for his authorship of a pamphlet entitled The Ten Cannots that emphasizes freedom and responsibility of the individual on himself. Originally published in 1916, it is often misattributed to Abraham Lincoln. The error apparently stems from a leaflet printed in 1942 by a conservative political organization called the Committee for Constitutional Government. The leaflet bore the title "Lincoln on Limitations" and contained some genuine Lincoln quotations on one side and the "Ten Cannots" on the other, with the attributions switched. The genuine Lincoln quotations may have been from an address on March 21, 1864 in which Lincoln said "Property is the fruit of labor; property is desirable; is a positive good in the world. That some should be rich shows that others may become rich, and hence, is just encouragement to industry and enterprise. Let not him who is houseless pull down the house of another; but let him labor diligently and build one for himself, thus by example assuring that his own shall be safe from violence when built." The mistake of crediting Lincoln for "The Ten Cannots" has been repeated many times since, notably by Ronald Reagan in his address to the 1992 Republican National Convention in Houston.
There are several minor variants of the pamphlet in circulation, but the most commonly accepted version appears below: