dissenting.
The word “discriminate” does not appear in the Equal Protection Clause.1 Since the plaintiffs' burden of proving a prima facie violation of that constitutional provision is significantly heavier than the burden of proving a prima facie violation of a statutory prohibition against discrimination,2 the constitutional holding in Geduldig v. Aiello, 417 *161U. S. 484 (1974), does not control the question of statutory-interpretation presented by this case. And, of course, when it enacted Title VII of the Civil Rights Act of 1964, Congress could not possibly have relied on language which this Court was to use a decade later in the Geduldig opinion.3 We are, therefore, presented with a fresh, and rather simple, question of statutory construction: Does a contract between a company and its employees which treats the risk of absenteeism caused by pregnancy differently from any other kind of absence discriminate against certain individuals because of their sex?
An affirmative answer to that question would not necessarily lead to a conclusion of illegality, because a statutory affirmative defense might justify the disparate treatment of pregnant women in certain situations. In this case, however, the company has not established any such justification. On the other hand, a negative answer to the threshold question would not necessarily defeat plaintiffs’ claim because facially neutral criteria may be illegal if they have a discriminatory effect.4 An analysis of the effect of a company’s rules relating to absenteeism would be appropriate if those rules referred only to neutral criteria, such as whether an absence was voluntary or involuntary, or perhaps particularly costly. This case, however, does not involve rules of that kind.
Rather, the rule at issue places the risk of. absence caused by pregnancy in a class by itself.5 By definition, such a *162rule discriminates on account of sex; for it is the capacity to become pregnant which primarily differentiates the female from the male. The analysis is the same whether the rule relates to hiring, promotion, the acceptability of an excuse for absence, or an exclusion from a disability insurance plan. Accordingly, without reaching the questions of motive, administrative expertise, and policy, which Mb. Justice Brennan so persuasively exposes, or the question of effect to which Mr. Justice Stewart and Mr. Justice Blackmun refer, I conclude that the language of the statute plainly requires the result which the Courts of Appeals have reached unanimously.
The word does, however, appear in a number of statutes, but has by no means been given a uniform interpretation in those statutes. Compare FTC v. Morton Salt Co., 334 U. S. 37, 44-45 (1948) (Robinson-Patman Act) with NLRB v. Great Dane Trailers, 388 U. S. 26, 32-35 (1967) (National Labor Relations Act).
Washington v. Davis, 426 U. S. 229, 238-248 (1976).
Quite clearly Congress could not have intended to adopt this Court’s analysis of sex discrimination because it was seven years after the statute was passed that the Court first intimated that the concept of sex discrimination might have some relevance to equal protection analysis. See Reed v. Reed, 404 U. S. 71 (1971).
Griggs v. Duke Power Co., 401 U. S. 424, 429-432 (1971).
It is not accurate to describe the program as dividing “ ‘potential recipients into two groups — pregnant women and nonpregnant persons.’ ” Ante, at 135. Insurance programs, company policies, and employment contracts all deal with future risks rather than historic facts. The elassifica*162tion is between persons who face a risk of pregnancy and those who do not.
Nor is it accurate to state that under the plan “ ‘[t]here is no risk from which men are protected and women are not.’ ” Ibid. If the word “risk” is used narrowly, men are protected against the risks associated with a prostate operation whereas women are not. If the word is used more broadly to describe the risk of uncompensated unemployment caused by physical disability, men receive total protection (subject to the 60% and 26-week limitations) against that risk whereas women receive only partial protection.