Thomas Aquinas

"The perfection of the human person lies in the proper functioning of reason."

"Beauty is the splendor of truth."

"A small act done with great love is far more valuable than a great act done with little love."

"The natural law prescribes that we preserve our own existence."

"Human laws should be ordered to the common good."

"The freedom of the will is the foundation of personal responsibility."

"Patience is not passive resignation but active virtue."

"The greatest happiness comes from contemplation of eternal truths."

"To love is to will the good of another."

"Evil is not a substance but rather the absence of a good that ought to be present."

"The soul is the form of the body; they are not two substances."

"God is pure being, ipsum esse subsistens, the subsistent act of being itself."

"The highest form of intellectual virtue is wisdom, which concerns divine and eternal things."

"Friendship is the most necessary thing for living."

"True peace comes not from the absence of conflict but from justice."

"The intellect is perfected by truth as the will is perfected by virtue."

"Every human act that proceeds from a deliberate choice is subject to moral evaluation."

"The greatest obstacle to truth is the assumption that we already possess it."

"Sorrow is the response of the will to a perceived evil."

"A thing cannot both be and not be at the same time and in the same respect."

"The end justifies the means is a principle that must be carefully considered in light of natural law."

"To be virtuous is not to suppress our passions but to direct them rightly."

"The act of love is the union of the will with the good."

"Human reason can grasp certain truths about God but not God's essence."

"The proper object of the intellect is being itself."

"Envy is destructive because it grieves at another's good as if it were an evil to oneself."

"The foundation of justice is good faith."

"True knowledge consists not merely in knowing facts but in understanding causes."

"The act of contemplation unites the mind with what it contemplates."

"Providence is God's loving care for all creation."