A gem cannot be polished without friction, nor a man perfected without trials.
Lucius Annaeus Seneca

At this camp I had the unique experience of showing all these seasoned Westerners that it was possible to make a fire by the friction of two sticks. This has long been a specialty of mine; I use a thong and a bow as the simplest way.
Ernest Thompson Seton

But heat can also be produced by the friction of liquids, in which there could be no question of changes in structure, or of the liberation of latent heat.
Hermann von Helmholtz

Change means movement. Movement means friction. Only in the frictionless vacuum of a nonexistent abstract world can movement or change occur without that abrasive friction of conflict.
Saul Alinsky

Heat can also be produced by the impact of imperfectly elastic bodies as well as by friction. This is the case, for instance, when we produce fire by striking flint against steel, or when an iron bar is worked for some time by powerful blows of the hammer.
Hermann von Helmholtz

I do not overlook the fact that the appearance of these new, free nations in the European political community not only celebrates the return of the prodigal son but also creates new sources of friction here and there.
Hjalmar Branting

I do remember the whole thing as being very argumentative, hot blooded... a permanent state of friction between Jon and Chris, Chris and me, me and Jon.
Bill Bruford

It's not the work which kills people, it's the worry. It's not the revolution that destroys machinery it's the friction.
Henry Ward Beecher

Iteration, like friction, is likely to generate heat instead of progress.
George Eliot

One might call habit a moral friction: something that prevents the mind from gliding over things but connects it with them and makes it hard for it to free itself from them.
Georg C. Lichtenberg

So, these political activities will create friction in and of themselves, and in this environment of friction there'll be additional violence.
John Abizaid

The keystone of successful business is cooperation. Friction retards progress.
James Cash Penney

The world is wide, and I will not waste my life in friction when it could be turned into momentum.
Frances E. Willard

They're keeping friction going between people from the East and the West. One thing we all got in common is your color, which is Black and Latino, which is our family.
Afrika Bambaataa

With a contained environment, there is the promise of friction. And that is where the drama comes from.
Bruce Greenwood