e "rigorous analysis" that Rule 23 compels merely for the sake of abstract notions of Title VII's objectives and purposes. Cf. Touche Ross & Co. v. Redington, 442 U.S. 560, 578, 99 S. Ct. 2479, 61 L. Ed. 2d 82 (1979) ("[G]eneralized references to the 'remedial purposes' of [a statute] will not justify re