"Person"

"PERSON signifies what is most perfect in all nature─that is, a subsistent individual of a rational nature. Hence, since everything that is perfect must be attributed to God, forasmuch as His essence contains every perfection, this name "person" is fittingly applied to God; not, however, as it is applied to creatures, but in a more excellent way; as other names also, which, while giving them to creatures, we attribute to God..." 

~St. Thomas Aquinas: Summa Theologiae I, Q. 29, A. 3.

"IT is a very significant fact that the idea of human personality and also the practical recognition of the dignity of human personality developed only during those centuries in which the dogmas of the Trinity and of the Incarnation were teaching Christendom the truths of divine personality."

~Jacques Maritain: Freedom in the Modern World.

"The sacrament of the Eucharist"

"THE CHURCH'S sacraments are ordained for helping man in the spiritual life. But the spiritual life is analogous to the corporeal, since corporeal things bear a resemblance to spiritual. Now it is clear that just as generation is required for corporeal life, since thereby man receives life; and growth, whereby man is brought to maturity: so likewise food is required for the preservation of life. Consequently, just as for the spiritual life there had to be Baptism, which is spiritual generation; and Confirmation, which is spiritual growth: so there needed to be the sacrament of the Eucharist, which is spiritual food."

~St. Thomas Aquinas: Summa Theologiae, III, Q. 73, A. 1.

The Institution of the Eucharist, by Joos van Wassenhove. 

Oil on wood, 1473-75; Galleria Nazionale delle Marche, Urbino.

On Original Sin

"THE whole order of original justice consists in man's will being subject to God: which subjection, first and chiefly, was in the will, whose function it is to move all the other parts to the end, as stated above (Q. 9, A. 1), so that the will being turned away from God, all the other powers of the soul become inordinate. Accordingly the privation of original justice, whereby the will was made subject to God, is the formal element in original sin; while every other disorder of the soul's powers, is a kind of material element in respect of original sin. Now the inordinateness of the other powers of the soul consists chiefly in their turning inordinately to mutable good; which inordinateness may be called by the general name of concupiscence. Hence original sin is concupiscence, materially, but privation of original justice, formally."

~St. Thomas Aquinas: S.T. I-II, Q. 82, A. 3.

"Divine help"

"MAN cannot even know truth without Divine help, as stated above (A. 1). And yet human nature is more corrupt by sin in regard to the desire for good, than in regard to the knowledge of truth."

~St. Thomas Aquinas: S.T. I-II, Q. 109, A. 2, ad. 3.

Charles Rice on Natural Law

Recommended reading:

50 Questions on the Natural Law: What It Is and Why We Need It, by Charles Rice.

• Amazon

• Ignatius Press

F.C. Copleston vs Bertrand Russell

Fr. Frederick C. Copleston vs Bertrand Russell - Part 1

A debate between historian of philosophy, F.C. Copleston, and
the well-known atheist philosopher and mathematician, Bertrand Russell,
on the existence of God.

Faith and reason

"SINCE therefore grace does not destroy nature but perfects it, natural reason should minister to faith as the natural bent of the will ministers to charity. Hence the Apostle says: "Bringing into captivity every understanding unto the obedience of Christ" (2 Cor 10:5). Hence sacred doctrine makes use also of the authority of philosophers in those questions in which they were able to know the truth by natural reason, as Paul quotes a saying of Aratus: "As some also of your own poets said: For we are also His offspring" (Acts 17:28). Nevertheless, sacred doctrine makes use of these authorities as extrinsic and probable arguments; but properly uses the authority of the canonical Scriptures as an incontrovertible proof, and the authority of the doctors of the Church as one that may properly be used, yet merely as probable. For our faith rests upon the revelation made to the apostles and prophets who wrote the canonical books, and not on the revelations (if any such there are) made to other doctors. Hence Augustine says (Epis. ad Hieron. xix, 1): "Only those books of Scripture which are called canonical have I learned to hold in such honor as to believe their authors have not erred in any way in writing them. But other authors I so read as not to deem everything in their works to be true, merely on account of their having so thought and written, whatever may have been their holiness and learning." "

~St. Thomas Aquinas: Summa Theologiae, I, q. 1, a. 8, ad. 2.