It is now generally accepted that the members of the Constituent Assembly who were charged with drafting the Constitution concentrated their efforts on formulating the ideals to be expressed in it at the expense of the institutional arrangements of the new Republic. This has generally been viewed as resulting from a combination of two factors: their weak grasp of the liberal principles underpinning liberal parliamentary democracy, and a concomitant error of judgement in assuming that sufficient stress on the ideals of the Constitution would guarantee the basis of a healthy democracy. This article sets out to examine the input of the most influential Catholic group, the dossettiani, and argues, against the error of judgement thesis, that in fact their rejection of the concept of the secular state was a more fundamental denial of important principles of a pluralist democracy than has usually been supposed. The article also places their contribution within the context of the Church's aim to create a ‘Christian civilization’, and further suggests that the model of Catholic Action which inspired its collateral vision of Catholic forces was corrosive of a pluralist vision of correct institutional arrangements. The article ends by suggesting that these factors may have weighed more heavily on subsequent distortions of Italian democracy than has so far been supposed.