'There is no need to intend what the Roman Church does; but what the true Church does, whatever that True Church is. Or what Christ instituted. Or what Christians do. Because these all amount to the same thing. You ask: What if someone intends to do what some particular and false church does, which he himself believes to be the true one - for example, the church of Geneva; and intends not to do what the Roman Church does? I answer, even that suffices. Because the man who intends to do what the church of Geneva does, intends to do what the universal Church does. For he intends to do what such-and-such a church does, because he believes it to be a member of the true Universal Church, granted that he is mistaken in recognising the True Church. For the error of the minister about the Church does not take away the efficacy of the Sacrament. Only defect of intention does that.'
- Saint Robert Bellarmine, de Sacramentis in genere chapter 27 paragraph 8.
This excellent new translation of Saint Bellarmine's classic exposition explains clearly why necessary intention in regard to the sacraments is very simple and easy to fulfil. Necessary sacramental intention means intending to 'do what the Church does' in a general sense, faciendi, quod facit Ecclesia, that is, to do what Christians do, or to do what Our Lord commands in the New Testament. One need not intend to do what the Church intends, but only intend to do what the Church (however that word is understood) does. Those who baptise must intend to baptise, those who celebrate the Eucharist must intend to celebrate the Eucharist, those who ordain must intend to ordain. No more. That's it. Period. Nothing could be simpler.
Saint Bellarmine also writes: 'The Council of Trent does not mention the purpose of the sacrament or say that the minister ought to intend to do what the Church intends but what the Church does. Moreover, what the Church does refers to the action, not the purpose. There is required the intention with regard to the action, not in so far as it is a natural action, but in so far as it is a sacred action or ceremony, which Christ instituted or Christians practise. If one intends to perform the ceremony which the Church performs, that is enough.'
Father Edward Yarnold affirms, 'A wrong understanding of the nature of a sacrament does not invalidate the sacrament... All that is necessary is 'the implicit intention of doing what the Church does without reference to the sacrament's effect, as if the minister were to say to himself: "I intend to perform the Christian rite of (say) baptism," and is therefore de facto doing what the Church does without attending to the fact... The traditional intention of doing what the Church does is apparently taken as synonymous with the intention of doing what Christ instituted (quod voluit Christus)... To sum up. There can be no doubt that Bellarmine held to the necessity of intending to do what the Church does only in the sense defined above: namely, that the minister is intending to perform a rite as practised by what he takes to be the Church. To deny the purpose of the sacrament does not extinguish this intention; nor even does the intention not to produce an effect intended by the Church.'
On the basis of this received teaching, the traditional theological position of the Western Church, sacraments are valid even if they are administered in heresy or in schism or outside the visible canonical boundaries of the Church, if they are administered by ministers with a false understanding of the very sacrament being administered, if they are received by a subject who holds a false understanding of the sacrament being administered, or if they are given or received by persons holding a false ecclesiology - so long as the proper matter (material thing or action) and form (words) necessary for the sacrament are used.
The rite used itself determines the necessary intention for validity. It is the objective action that matters; what one subjectively thinks about it does not affect validity. In the objective action, Our Lord is always infallibly the true minister of the sacrament. When the basic rite is observed, the outward and visible signs used as He commands, Our Blessed Lord promises that He will give His grace, which promise is the covenant of the sacramental system. The human minister is but an instrument, an agent; Christ is the actual minister, the one who truly celebrates and confers grace.
This quintessential theological instruction means, for example, that all sectarian Baptism given outside the visible Catholic Apostolic Church is valid so long as it is Trinitarian in form and administered with water - and is thus Christ's and the Church's one Baptism. It means that the Eucharist and Holy Orders celebrated by individual ministers or ecclesial bodies holding heterodox views on these very sacraments themselves are always valid, so long as the necessary matter and form are used in the celebration of the Eucharist and Holy Orders and the unbroken succession of Orders with necessary matter and form is conferred upon the celebrant in each and every instance.
A validly ordained priest always validly celebrates the Eucharist regardless of his own beliefs or views on the Church or the sacrament, so long as he employs the Words of Institution from Our Lord and real wheaten bread and fermented grape wine in the consecration. A validly consecrated bishop always validly ordains regardless of his own beliefs or views on the Church or the sacrament, so long as he employs a rite for ordination that contains both the laying on of hands on the male baptised candidate and prayer for the grace of the Order being conferred. In both cases, this is all that the New Testament and the universal Tradition require.
Saint Bellarmine therefore also completely eviscerates the erroneous assertions of Pope Leo XIII in 1896 regarding Anglican Orders.