Abstract: Last year’s decision in Bostock v. Clayton County was an important victory for gay and transgender workers—but the Supreme Court’s textual analysis has failed to persuade a number of thoughtful commentators, and it threatens to leave anti-discrimination law in disarray. The root of the problem is that Bostock trumpeted a “simple test” of but-for causation that could not alone explain the correctness of the results that the Court reached. This explanatory gap not only has left Bostock’s holding vulnerable to attack, but also has engendered uncertainty about the panoply of disparate-treatment questions for which Bostock now provides the governing precedent. Indeed, because Bostock took it upon itself to interpret Title VII from textualist first principles, its analysis will orient—and perhaps disorient—judicial approaches to all manner of disparate-treatment claims for many years to come. What disparate-treatment law needs, but the Court has thus far failed to provide, is a coherent, general, and textually grounded account of what it means for a decision to be made “because of” a protected characteristic—one that accords with Bostock’s motivating intuitions but transcends its overly simplistic account of its own reasoning. Drawing on a venerable body of work in analytic philosophy concerning “determinable” properties and their corresponding “determinates,” this Article develops an account that meets that need. In brief, this “dimensional” account of disparate treatment recognizes a decision as being made “because of [an] individual’s X” whenever the decision is motivated by a property that characterizes the individual in the dimension of X—regardless of whether a different decision would have been made if the individual had belonged to any other determinate class that is defined along that dimension. After introducing and defending this analysis, the Article traces its implications for a wide range of current controversies—involving bisexuality, pregnancy, race and gender stereotypes, and more. Finally, the Article defends the dimensional account and its implicit application in Bostock on textualist terms. It argues that the account captures the meaning that an “ordinary reader” would ascribe to Congress’s enactment of a disparate-treatment statute—so long as the reader construes the statute in light of characteristic features of legislative communication, as sophisticated accounts of modern textualism would demand.