See also:
CLEMENT XI, Concerning Truths which Necessarily Must be Explicitly Believed * [Response of the Sacred Office to the Bishop of Quebec, Jan. 25, 1703]
Denz. 1349a (Denz.-Schon. 2380 ): Whether a minister is bound, before baptism is conferred on an adult, to explain to him all the mysteries of our faith, especially if he is at the point of death, because this might disturb his mind. Or, whether it is sufficient, if the one at the point of death will promise that when he recovers from the illness, he will take care to be instructed, so that he may put into practice what has been commanded him.
Resp. A promise is not sufficient, but a missionary is bound to explain to an adult, even a dying one who is not entirely incapacitated,
the mysteries of faith which are necessary by a necessity of means, as are especially the mysteries of the Trinity and the Incarnation.
[Response of the Sacred Office, May 10, 1703]
Denz. 1349b (Denz.-Schon. 2381): Whether it is possible for a crude and uneducated adult, as it might be with a barbarian, to be baptized, if there were given to him only an understanding of God and some of His attributes, especially His justice in rewarding and in punishing, according to this remark of the Apostle "He that cometh to God must believe that he is and that he is a rewarder'; [Heb . 11:23], from which it is inferred that a barbarian adult, in a certain case of urgent necessity, can be baptized although he does not believe explicitly in Jesus Christ.
Resp. A missionary should not baptize one who does not believe explicitly in the Lord Jesus Christ, but is bound to instruct him about all those matters which are necessary, by a necessity of means, in accordance with the capacity of the one to be baptized.
http://www.catecheticsonline.com/SourcesofDogma14.phphttp://www.catho.org/9.php?d=byc#cug