CHAPTER IV: ON THE SUBJECT OF THE EUCHARIST

Only a baptized man can receive the Eucharist sacramentally; because only the baptized is capable of the Sacraments. Hence an unbeliever receiving the Eucharist would indeed receive it truly, but only materially, not however sacramentally. But a baptized man who is indisposed receives indeed sacramentally, but not spiritually, i.e. he receives, but without fruit. But a baptized man who is disposed receives both sacramentally and spiritually, or with fruit. - Trent.¹

It must be treated 1° of the obligation of receiving the Eucharist; 2° of the disposition required for receiving it worthily.