| A | B |
| Reason | Man's intellectual power or faculty |
| Polytheism | Belief in many Gods |
| Natural Revelation | What can be known about God by studying his creation. |
| Science | Method of understanding the laws of nature through observation, hypothesis, and experiment. |
| Dogma | Revealed truth solemnly defined by the Church. |
| Scientism | Error that limits human reason to only those things that can be observed and measured. |
| Atheism | Denial in the existence of God. |
| Faith | Theological virtue by which one believes God's Revelation. |
| Theology | Faith seeking understanding. |
| Natural law | Ethical knowledge written on the human heart. |
| Revelation | God's communication of himself through his words and deeds. |
| Grace | God's divine life present in the soul. |
| Mysteries | Supernatural truths that transcend human reason. |
| Agnosticism | A belief that the existence of God cannot be known or proven.p |
| Deism | A form of rationalism that admits a natural, rational religion, and therefore a belief in God. |
| Fideism | A philosophy that accepts religious beliefs without grasping their intellectual content. |
| Five Ways | St. Thomas' five proposals for how the existence of God can be know through reason |
| Rationalism | Strict rationalism consists in judging everything solely and exclusively according to philosophical or scientific reason. |
| Scholasticism | The system of philosophical and theological inquiry developed in the medieval schools of Christian Europe. |
| Philosophy | Derived from the Greek word " love of knowledge", is the pursuit of truth and understanding through the application of human reason. |