LIMITATION OF HOURS OF LABOR for such attitude. But Mr. Justice Peckham's attitude is aroused only by the sup posed necessity of supporting the law as a health law, by the assertion that ' ' if the man works ten hours a day it is all right, but if ten and a half or eleven, his health is in danger, and his bread may be unhealthy, and, therefore, he shall not be permitted to do it." "This," the opinion adds, " we think is unreasonable and entirely arbitrary." Apply this method of reasoning by analogy : a person twenty years and 364 days old has not sufficient discretion to make a binding contract, while a person twenty years and 366 days old has such discretion; this we think is unreasonable and entirely arbitrary, and so forth. In this way every positive legal limitation can be reduced to an ab surdity. It is easy to demolish a law by advancing for its support unreasonable asser tions which no one has really made, and then declaring it to be arbitrary by reason of such assertion. Not quite so strongly, but still to a cer tain degree, this observation applies to the argument advanced in the opinion, that upon the assumption that any law must be valid which may be said to tend to make people healthy, conduct, properly so called, as well as contract, would come under the restrictive sway of the legislature. "Not only the hours of employees, but the hours of employers could be regulated and doc tors, lawvers, scientists, all professional men as well as athletes and artisans could be forbidden to fatigue their brains and bodies by prolonged hours of exercise, lest the fighting strength of the state 'be impaired." What police legislation can stand if it be contended that the admission of legislative power involves the admission of the right to exercise it in an arbitrary or absurd man ner, and that the inadmissibility of such exercise conversely demands the denial of the power, even though moderately exer cised? Mr. Justice Peckham himself, in an other case, refuted this argument when he said: "A statute or a regulation provided
for therein, is frequently valid, or the reverse, according as the fact may be, whether it is a reasonable or an unreasonable exercise of legislative power over the subject matter involved, and in many cases questions of degree are the controlling ones by which to determine the validity or the reverse, of legislative action" (179 U. S. 287, p. 301). The court, it should be specially noted, does not intimate that the number of hours fixed upon is unreasonably small, so as to revolutionize existing arrangements, or to jeopardize the profits of the trade, or to leave the public short of the needed supply of bread. IV Perhaps the essential argument of the prevailing opinion may be reduced to the following propositions : First, the mere fact that a measure claims to subserve the public welfare does not en sure its validity as a legitimate exercise of the police power. This proposition is true, but of little practical value. Second, the fact that a measure tends re motely to promote health or safety is like wise not conclusive of its validity, since such effect in a very slight degree might be predicted of the most unwarrantable and oppressive interferences with private liberty and property. The truth of this proposi tion must likewise be conceded. Third, the test of the reality of the danger to the public health or safety and of its sufficiency to warrant interference with in dividual liberty is common knowledge or understanding, of which the court may take judicial notice. Fourth, according to common knowledge or understanding, the trade of bakers is not so unsanitary that a compulsory limitation of hours of labor can be looked upon as a measure reasonably necessary to preserve their health . It is upon these propositions that the strength or the weakness of the decision must rest. Is the test of common understanding
