Philosophical Perspectives on Truth and Knowledge
Two Meanings of Coherence
- The first meaning refers to internal consistency: no contradiction between the subject and predicate of a proposition, and no contradiction between two different propositions. It relates to consistency. For example, it is coherent to say, “The Bushmen are nice,” because there is no inherent contradiction between ‘Bushman’ and ‘nice’. Conversely, it might be incoherent to assert contradictory predicates about the same subject, such as “People from Zamora are Andalusians and are blond,” if these attributes are mutually exclusive in the given context.
- The second meaning refers to the derivability or deductibility of one proposition from another. This occurs in logical entailments, such as (p ∧ q) → ¬(¬p ∨ ¬q), or in deductive reasoning. For instance, if skin color is strictly inherited based on simple genetic rules, concluding that Andrew and Elena, who are both white, cannot be the biological parents of a black child demonstrates coherence as deductibility.
Truth as Consensus Theory
Truth is defined as the consensus reached, or potentially reachable, through dialogue. This dialogue must ideally be held under conditions of freedom and equality, involving all relevant participants concerned with the claim.
Challenges to Consensus Theory
Several problems challenge the theory of truth as consensus:
- Possibility of Consensus: A primary challenge concerns whether genuine consensus is actually achievable.
- In principle, it could be possible, just as human communication itself is possible. Furthermore, the concept of a ‘performative contradiction’ suggests that arguing against the possibility of consensus implicitly acknowledges its potential by engaging in the very process aimed at reaching agreement.
- However, achieving consensus might be practically impossible because participants rarely start from identical positions, and external factors or power imbalances can distort the dialogue, preventing true, uncoerced agreement.
- Consensus and Truth: Another significant problem is that consensus does not guarantee truth. Agreements reached by consensus can change over time as new information emerges or perspectives shift. What was once accepted as true by consensus may later be rejected, meaning past consensuses are often superseded.
Utilitarian Theory of Truth
In this view, the primary value of knowledge lies not in its absolute truth or falsity, but in its utility. Knowledge is considered ‘true’ if it is useful and produces benefits for those who hold it. This concept has roots in utilitarian moral theory, which posits that the ‘good’ is that which is useful (often defined as maximizing well-being).
This theory of truth is notably defended by William James (often associated more broadly with pragmatism). For example, James argued for the ‘truth’ of believing in God by citing its usefulness: belief provides comfort, hope, and other psychological benefits, while disbelief may lead to despair. The practical benefits of belief lend it a form of truth in this framework.
Pragmatic Theory of Truth
Epistemological pragmatism can be seen as a form of radical empiricism. Its fundamental thesis relates truth to practical consequences and successful application. A theory is considered true if putting it into practice yields positive, successful results. It also holds that a theory is true if its predictions align with experimental outcomes and practical verification.
Understanding Skepticism
Skepticism refers to any philosophical stance that questions or denies the possibility of attaining certain knowledge or truth. It exists on a spectrum, from methodological doubt used to scrutinize claims, to radical skepticism (associated with figures like David Hume in certain interpretations) which denies the possibility of any certain truth.
Skepticism is often the conclusion reached after examining the limits of knowledge, rather than a starting assumption. Arguments for skepticism require justification; it is typically not adopted without reason.
Truth and Perceptual Phenomena
A phenomenon is understood as the object of perception, such as a mountain, a brain tumor, or the aurora borealis. Establishing the truth about such phenomena often involves direct observation, measurement, weighing, description, and other empirical methods.
Ideally, we might wish to perceive all aspects of reality directly, including the underlying causes of phenomena. It is often conceived that a being like God possesses such direct, comprehensive perception. Since humans lack this capacity, we rely on ingenuity and tools to acquire knowledge about things we cannot perceive directly.
The primary instrument for rational explanation beyond direct perception is theory. For instance, tumors might be explained by oncogene theory, mountain formation by plate tectonics, and the aurora borealis by the interaction of solar wind with Earth’s magnetic field. Theories are rational frameworks that explain observable phenomena by positing underlying, often unobservable, causes or mechanisms. They tell us how or why things happen or why things are the way they are.