Mugler v. Kansas, 133 U.S. 623.
 Fertilizing Co. v. Hyde Park, 97 U.S. 659.
 Slaughter House Cases, 16 Wallace 78, decided in 1873.
 94 U.S. 113.
 Chicago, Milwaukee & St. Paul Ry. v. Minnesota, 134 U.S. 461, decided March 24, 1890.
 Noble State Bank v. Haskell, 219 U.S. 104.
 See the extraordinary case of Douglas v. Kentucky, 168 U.S. 488, which must be read in connection with Gregory v. Trustees of Shelby College, 2 Metc. (Kentucky) 589.
 Brass v. North Dakota, 133 U.S. 391.
 169 U.S. 466.
 The Federalist, No. LXXVIII.
 221 U.S. 91.
 60th Congress, 2d Session, Senate, Report No. 848, Adverse Report by Mr. Nelson, Amending Anti-trust Act, January 26, 1909, page 11.
 Standard Oil Company v. United States, 221 U.S. 1.
 United States v. American Tobacco Company, 221 U.S. 191, 192.
 221 U.S. 69.
 To Spencer Roane, Sept. 6, 1819, Ford, 10, 141.
THE SOCIAL EQUILIBRIUM
I assume it as self-evident that those who, at any given moment, are the strongest in any civilization, will be those who are at once the ruling class, those who own most property, and those who have most influence on legislation. The weaker will fare hardly in proportion to their weakness. Such is the order of nature. But, since those are the strongest through whom nature finds it, for the time being, easiest to vent her energy, and as the whole universe is in ceaseless change, it follows that the composition of ruling classes is never constant, but shifts to correspond with the shifting environment. When this movement is so rapid that men cannot adapt themselves to it, we call the phenomenon a revolution, and it is with revolutions that I now have to do.
Nothing is more certain than that the intellectual adaptability of the individual man is very limited. A ruling class is seldom conscious of its own decay, and most of the worst catastrophes of history have been caused by an obstinate resistance to change when resistance was no longer possible. Thus while an incessant alteration in social equilibrium is inevitable, a revolution is a problem in dynamics, on the correct solution of which the fortunes of a declining class depend.
For example, the modern English landlords replaced the military feudal aristocracy during the sixteenth century, because the landlords had more economic capacity and less credulity. The men who supplanted the mediaeval soldiers in Great Britain had no scruple about robbing the clergy of their land, and because of this quality they prospered greatly. Ultimately the landlords reached high fortune by controlling the boroughs which had, in the Middle Ages, acquired