Doctrinal Catechism (1876):
Q. Do Catholics charge all that are apparently out of their communion with the crimes of heresy and schism, and consequently exclude them from salvation
A. No; all baptized children who die before they sin mortally, and before they embrace and believe error, are members of the true Church. Again, all those sincere people belong to the soul of the Church, who, being baptized, and believing the great fundamental truths of Christianity, and who are prevented from believing it in all its details, not by carelessness, nor temporal interest, nor human respect, nor the spirit of obstinacy, nor by malice, but simply because they never doubted, and never had sufficient means of knowing the truth, which they would embrace at once, and with gladness, could they only discover it,*—*all these, we say, belong to the soul of the Church, and will be saved, if they lead good lives and do not violate God’s law.
[size=2] Q. *What do you mean by the soul of the Church?
*A. All those belong to the body of the Church who are openly professing Catholics; to the soul of the Church belong all such as I have above described, who, being baptized, and believing the fundamental truths of religion, are living separate from the body of the Church, not by any fault of their own, but purely by not having sufficient means to lead them into a knowledge of the whole truth.