In An Essay in Aid of a Grammar of Assent (1870), Saint John Henry Newman explores how the human mind moves from considering ideas to genuinely believing them. Rather than viewing belief as a gradient of logical probabilities, Newman argues that assent is unconditional—we either accept a proposition as true or we do not.
Newman breaks down the modes, levels, and processes of belief through key distinctions in Apprehension, Assent, and Inference.
1. Apprehension: The Basis of Assent
Before the mind can assent to a statement, it must first grasp its meaning. Newman calls this Apprehension. Depending on whether the mind apprehends an abstract concept or a concrete reality, assent takes one of two primary forms: Notional Assent or Real Assent.
2. The Two Primary Kinds of Assent
A. Notional Assent (Theoretical & Abstract Belief)
Notional assent occurs when the mind accepts propositions about abstract ideas, generalities, or logical definitions. It engages the theological or analytical intellect rather than the imagination.
Newman categorizes Notional Assent into five distinct levels/modes:
- Profession: Acquiescence to statements as a matter of custom, manners, or social convention without deep individual reflection (e.g., agreeing with a political platitude).
- Credence: Accepting general facts or common knowledge built on everyday information, history, or literature without personal experience (e.g., believing that Julius Caesar crossed the Rubicon).
- Opinion: Assenting to a statement as the most likely or probable among competing theories, while acknowledging that it could be open to revision (e.g., holding a favorite economic theory).
- Presumption: Accepting fundamental principles or background assumptions that cannot be strictly proven but are taken for granted (e.g., trust in the reliability of memory or the uniformity of physical laws).
- Speculation: Deep mental reflection on abstract theoretical frameworks, mathematics, theology, or philosophy (e.g., assenting to a complex mathematical theorem or theological dogma as logically consistent).
B. Real Assent (Concrete & Experiential Belief)
Real assent occurs when a proposition is directed toward concrete things, personal experiences, or individual realities. It moves beyond mere theoretical agreement to engage the imagination, emotions, and memory, directly influencing personal conduct and devotion.
- Example: Notional assent is knowing theoretically that suffering exists; Real assent occurs when you witness or experience tragedy yourself, transforming abstract knowledge into a felt reality.
- Religious context: Notional assent accepts a theological dogma as an abstract definition; Real assent encounters God as a living personal reality.
3. Inference vs. Assent
Newman distinguishes Assent (unconditional acceptance of a truth) from Inference (conditional acceptance based on arguments or premises):
- Formal Inference: Deductive, explicit logic (syllogisms or mathematical proofs). Newman notes that while useful, paper logic alone rarely drives real-life belief or human action.
- Informal Inference: The mind's cumulative assessment of converging probabilities—a multitude of independent, subtle indicators that together build an overwhelming case.
- Natural Inference: An instantaneous, implicit leap from concrete perceptions directly to conclusions based on lived experience (e.g., smelling smoke and immediately inferring fire without constructing a formal logical proof).
4. Certitude and the "Illative Sense"
How do humans bridge the gap between accumulated probabilities (Inference) and absolute conviction (Assent)? Newman identifies two key concepts:
- The Illative Sense: The personal, organic faculty of the human mind that evaluates informal evidence, context, intuition, and memory as a cohesive whole. It allows the mind to judge when converging probabilities are sufficient to make an unconditional leap of faith.
- Certitude: The highest level of Real Assent—an indefectible, unshakeable conviction that has survived conscious reflection and testing, yielding permanent personal peace and truth.