Epistemology is the branch of philosophy which studies the nature, origin, and scope of knowledge. Knowledge is, from an epistemological standpoint, distinguished from mere belief by justification, warrant, or other such property the having of which is conducive to getting at the truth.
Knowledge in the sense of “understanding of a fact or truth” can be divided into a posteriori knowledge, based on experience or deduction and a priori knowledge from introspection, axioms, or self-evidence. Knowledge can also be described as a psychological state, since in a strict sense there can never be a posteriori knowledge proper (see relativism). Much of the disagreement about “proofs” of God’s existence is due to different conceptions not only of the term “God” but also the terms “proof”, “truth”, and “knowledge”.
Religious belief from revelation or enlightenment (satori) can fall into either the first category, a posteriori knowledge, if rooted in deduction or personal revelation, or the second, a priori class of knowledge, if based on introspection.
Different conclusions as to the existence of God often rest on different criteria for deciding what methods are appropriate for deciding if something is true or not, including:
- whether logic counts as evidence concerning the quality of existence
- whether subjective experience counts as evidence for objective reality
- whether either logic or evidence can rule in or out the supernatural
- whether an object of the mind is accepted for existence
- whether a truthbearer can justify.
Arguments grounded in personal experiences
- An argument for God is often made from an unlikely complete reversal in lifestyle by an individual towards God. Paul of Tarsus, a persecutor of the early Church, became a pillar of the Church after his conversion on the road to Damascus. Modern day examples in Evangelical Protestantism are sometimes called “Born-Again Christians“.
- The Scottish School of Common Sense led by Thomas Reid taught that the fact of the existence of God is accepted by people without knowledge of reasons but simply by a natural impulse. That God exists, this school said, is one of the chief metaphysical principles that people accept not because they are evident in themselves or because they can be proved, but because common sense obliges people to accept them.
- The Argument from a Proper Basis argues that belief in God is “properly basic”; that it is similar to statements like “I see a chair” or “I feel pain”. Such beliefs are non-falsifiable and, thus, neither provable nor disprovable; they concern perceptual beliefs or indisputable mental states.
- In Germany, the School of Friedrich Heinrich Jacobi taught that human reason is able to perceive the suprasensible. Jacobi distinguished three faculties: sense, reason, and understanding. Just as sense has immediate perception of the material so has reason immediate perception of the immaterial, while the understanding brings these perceptions to a person’s consciousness and unites them to one another.
- God’s existence, then, cannot be proven (Jacobi, like Immanuel Kant, rejected the absolute value of the principle of causality), it must be felt by the mind.
- In Emile, Jean-Jacques Rousseau asserted that when a person’s understanding ponders over the existence of God it encounters nothing but contradictions; the impulses of people’s hearts, however, are of more value than the understanding, and these proclaim clearly the truths of natural religion, namely, the existence of God and the immortality of the soul.
- The same theory was advocated in Germany by Friedrich Schleiermacher, who assumed an inner religious sense by means of which people feel religious truths. According to Schleiermacher, religion consists solely in this inner perception, and dogmatic doctrines are inessential.
- Many modern Protestant theologians follow in Schleiermacher’s footsteps, and teach that the existence of God cannot be demonstrated; certainty as to this truth is only furnished to people by inner experience, feeling, and perception.
- Modernist Christianity also denies the demonstrability of the existence of God. According to them, one can only know something of God by means of the vital immanence, that is, under favorable circumstances the need of the divine dormant in one’s subconsciousness becomes conscious and arouses that religious feeling or experience in which God reveals himself. In condemnation of this view the Oath Against Modernism formulated by Pius X, a Pope of the Catholic Church, says: “Deum … naturali rationis lumine per ea quae facta sunt, hoc est per visibilia creationis opera, tanquam causam per effectus certo cognosci adeoque demostrari etiam posse, profiteor.” (“I declare that by the natural light of reason, God can be certainly known and therefore his existence demonstrated through the things that are made, i.e., through the visible works of creation, as the cause is known through its effects.”)