The drive to unitary or comprehensive education to the age of 16, the single most significant measure introduced by LOGSE, was a logical move away from the perceived weaknesses and injustices of the previous division at age 14 between a prestige academic route, the Bachillerato, and a low-prestige vocational route (none the less criticized for being over-academic), Formación Profesional, and it accorded with the practice of many other developed countries. Like LGE before it, LOGSE is arguably based on a ‘deficit’ model of Spanish education which is perceived as being in various ways ‘backward’ in comparison with its more ‘modern’ neighbours, and needing to be brought more into line with ‘modern’ practice-but at the risk of being insufficiently critical of the ‘modern’. More positively, different models of comprehensive education were piloted over several years prior to legislation. But it is arguable whether the discussions leading up to reform were sufficiently informed by any evaluation of comparable international practice that took systematic account of and responded to evidence of disillusion with aspects of comprehensive education in countries such as England and Wales. Some of the most critical analysis proceeded from the relatively young discipline (in Spain) of educational sociology, and the work of one of that discipline’s foremost exponents, Fernández Enguita, raises important issues reminiscent of the debates surrounding comprehensive education in Great Britain some thirty years previously. This chapter investigates the implications of the offer of options (different models of optionality were tested in different regions of Spain, namely Cataluña and País Vasco, and in the area administered directly by the Ministry) in relation to principles of comprehensivization and individualization of the curriculum. Secondary education in Cataluña is to be organized in terms of credits or termly modules (with optionality increasing from 27 per cent of the curriculum in the first cycle to 35 per cent in the second), each of 35 teaching hours, whereas in other areas of Spain the curriculum will be organized in terms of ‘areas of knowledge’.