Louis Brandeis is often celebrated for his advocacy in Muller v. Oregon, and the so-called Brandeis Brief. As David Bernstein has pointed out, most of the brief was junk social science. In case you were wondering, here is the opening paragraphs of his lead argument section about the dangers of long hours for working women.

I. The Dangers of Long Hours

A. Causes

(1) Physical Differences Between Men and Women

The dangers of long hours for women arise from their special physical organization taken in connection with the strain incident to factory and similar work.

Long hours of labor are dangerous for women primarily because of their special physical organization. In structure and function women are differentiated from men. Besides these anatomical and physiological differences, physicians are agreed that women are fundamentally weaker than men in all that makes for endurance: in muscular strength, in nervous energy, in the powers of persistent attention and application. Overwork, therefore, which strains endurance to the utmost, is more disastrous to the health of women than of men, and entails upon them more lasting injury ….

Compare this with Justice Sutherland’s opinion in Adkins v. Children Hospital:

In the Muller case, the validity of an Oregon statute, forbidding the employment of any female in certain industries more than ten hours during anyone day was upheld. The decision proceeded upon the theory that the difference between the sexes may justify a different rule respecting hours of labor in the case of women than in the case of men. It is pointed out that these consist in differences of physical structure, especially in respect[p553] of the maternal functions, and also in the fact that, historically, woman has always been dependent upon man, who has established his control by superior physical strength. The cases of Riley, Miller, and Bosley follow in this respect the Muller case. But the ancient inequality of the sexes, otherwise than physical, as suggested in the Muller case (p. 421) has continued “with diminishing intensity.” In view of the great — not to say revolutionary — changes which have taken place since that utterance, in the contractual, political and civil status of women, culminating in the Nineteenth Amendment, it is not unreasonable to say that these differences have now come almost, if not quite, to the vanishing point. In this aspect of the matter, while the physical differences must be recognized in appropriate cases, and legislation fixing hours or conditions of work may properly take them into account, we cannot accept the doctrine that women of mature age, sui juris, require or may be subjected to restrictions upon their liberty of contract which could not lawfully be imposed in the case of men under similar circumstances. To do so would be to ignore all the implications to be drawn from the present day trend of legislation, as well as that of common thought and usage, by which woman is accorded emancipation from the old doctrine that she must be given special protection or be subjected to special restraint in her contractual and civil relationships. In passing, it may be noted that the instant statute applies in the case of a woman employer contracting with a woman employee as it does when the former is a man.

And for reasons I cannot recall, Justice Brandeis recused in Adkins.

Years ago, I saw Justice Ginsburg preside over a reenactment of Muller v. Oregon. It was awesome to see RBG favorably cite Lochner, and note how the arguments in Muller deemed women inferior.