“We do what we can do means what exactly means, that we do what we can do.”

Address to his branch and flight control team on the Monday morning following the Apollo 1 disaster (30 January 1967), known as "The Kranz Dictum"; as published in Failure Is Not An Option : Mission Control from Mercury to Apollo 13 and Beyond (2000) by Gene Kranz, p. 204. The phrase "tough and competent" was echoed by NASA Director Sean O'Keefe following the Space Shuttle Columbia disaster, adding that "these words are the price of admission to the ranks of NASA, and we should adopt it that way."
Context: Spaceflight will never tolerate carelessness, incapacity, and neglect. Somewhere, somehow, we screwed up. It could have been in design, build, or test. Whatever it was, we should have caught it.
We were too gung ho about the schedule and we locked out all of the problems we saw each day in our work. Every element of the program was in trouble and so were we. The simulators were not working, Mission Control was behind in virtually every area, and the flight and test procedures changed daily. Nothing we did had any shelf life. Not one of us stood up and said, "Dammit, stop!"
I don't know what Thompson's committee will find as the cause, but I know what I find. We are the cause! We were not ready! We did not do our job. We were rolling the dice, hoping that things would come together by launch day, when in our hearts we knew it would take a miracle. We were pushing the schedule and betting that the Cape would slip before we did.
From this day forward, Flight Control will be known by two words: "Tough and Competent." Tough means we are forever accountable for what we do or what we fail to do. We will never again compromise our responsibilities. Every time we walk into Mission Control we will know what we stand for.
Competent means we will never take anything for granted. We will never be found short in our knowledge and in our skills. Mission Control will be perfect.
When you leave this meeting today you will go to your office and the first thing you will do there is to write "Tough and Competent" on your blackboards. It will never be erased. Each day when you enter the room these words will remind you of the price paid by Grissom, White, and Chaffee. These words are the price of admission to the ranks of Mission Control.

The Complete Neurotic's Notebook (1981), Neurotics and neurosis

Think Better: An Innovator's Guide to Productive Thinking

Massive Change (2004)

1810s, What do we mean by the American Revolution? (1818)
Context: The American Revolution was not a common event. Its effects and consequences have already been awful over a great part of the globe. And when and where are they to cease?
But what do we mean by the American Revolution? Do we mean the American war? The Revolution was effected before the war commenced. The Revolution was in the minds and hearts of the people; a change in their religious sentiments of their duties and obligations. … This radical change in the principles, opinions, sentiments, and affections of the people, was the real American Revolution.

Source: The Future Of Life