This paper addresses the question of whether the political debate concerning comprehensive schooling in the Netherlands between 1965 and 1979 was obscured by incompatible meanings of the concept of "equal opportunity". On the basis of an analysis of ministerial plans and parliamentary debates the conclusion is drawn that Dutch politicians were using different but not incompatible meanings of this concept. The debate shows a remarkable continuity, with the meritocratic meaning of "equal opportunity" unceasingly dominating the debate, while an egalitarian meaning remained unused. The analysis, moreover, shows that in the polarised political climate of the 1970s right-wing liberal opponents of comprehensive schooling created a mist by accusing their social-democratic adversaries of relying on an egalitarian meaning of the concept. This strategy appealed to the denominational parties, and may therefore have influenced the outcome of the debate with the consequence of comprehensive schooling being removed from the political agenda.