Scepticism, within the realm of philosophy, interrogates the possibility of certain knowledge, providing a platform for debate on what can be known and how. It scrutinises the foundations and extents of our claims to knowledge, presenting a crucial and rigorous test for epistemological theories.
Historical Context of Scepticism
Philosophical scepticism dates back to antiquity, with its roots entangled in the profound questions posed by early philosophers.
- Pyrrhonian Scepticism: Advocated by Pyrrho, this strand of scepticism is rooted in suspending judgment to achieve mental peace.
- Academic Scepticism: Stemming from Plato's Academy, this approach claims that acquiring certain knowledge is beyond human capacity.
These ancient sceptical schools laid the groundwork for future epistemological inquiry by persistently challenging the assumptions underlying knowledge claims.
Types of Scepticism
Radical Scepticism
Radical scepticism calls into question the possibility of any knowledge, whether it be empirical or a priori.
Local Scepticism
Unlike its radical counterpart, local scepticism limits its scope to particular kinds of knowledge, such as ethical, religious, or metaphysical claims.
Arguments from Illusion
One of the cornerstones of sceptical argumentation is the assertion that our sensory experiences are not always reliable, casting doubt on the direct knowledge of reality.
The Argument from Illusion
- Premise: Since our senses can be deceived, as in the case of a straight stick appearing bent in water, our perception may not always align with reality.
- Conclusion: If our sensory experiences are not always reliable, then they cannot serve as an infallible foundation for knowledge about the external world.
The Problem of Hallucination
Hallucinations further aggravate the sceptical dilemma as they suggest that experiences cannot be taken as veridical representations of the world, given that they can occur without any corresponding external reality.
Responses to Scepticism
Philosophers have crafted numerous responses to scepticism, each trying to salvage our claims to know from the sceptical onslaught.
Descartes' Methodological Scepticism
Descartes used scepticism as a tool to discard all uncertain beliefs, aiming to find an undeniable foundation for knowledge. His famous conclusion, "I think, therefore I am," serves as an example of knowledge immune to sceptical doubt.
Moore's Common Sense Philosophy
Moore countered scepticism by turning to everyday beliefs that we confidently hold to be true, asserting that these beliefs are more certain than the sceptical hypotheses that question them.
Implications of Scepticism for Knowledge and Belief
The implications of scepticism are profound and pervasive, stretching across the entire landscape of epistemology.
The Knowledge Claim Challenge
Scepticism calls into question the traditional tripartite definition of knowledge as justified true belief, suggesting that this formulation may not be sufficient to overcome sceptical challenges.
The Basis of Rational Belief
Scepticism does not merely refute certain knowledge; it also urges us to reflect on what grounds we can maintain rational belief.
The Problem of External World Scepticism
Concerns raised by external world scepticism go to the heart of philosophical enquiry, questioning the existence and nature of the world beyond our subjective experiences.
- Philosophical Implication: This form of scepticism leads to a radical reconsideration of what we claim to know about the world.
- Practical Aspect: Despite profound doubts about the external world, we carry on with our daily lives, implicitly trusting our senses and perceptions.
The Role of Scepticism in Philosophy
Scepticism not only challenges philosophical positions but also refines them by forcing a rigorous examination and justification of our beliefs.
- Constructive Role: By undermining certainty, scepticism compels philosophers to construct more solid and defensible knowledge theories.
- Philosophical Inquiry: The relentless questioning characteristic of scepticism is a powerful catalyst for philosophical progress.
Philosophical Scepticism vs. Ordinary Doubt
While both forms of doubt serve significant purposes, it's crucial to distinguish between philosophical scepticism and the everyday doubts that pervade our practical decision-making processes.
- Scope: Philosophical scepticism has a more profound and comprehensive scope than ordinary doubt, which typically pertains to particular beliefs or decisions.
- Impact: Sceptical doubts can paralyse philosophical debates if left unchecked, while ordinary doubts are integral to rational thought and enquiry.
Overcoming Scepticism
Philosophers have developed several strategies to counter scepticism, hoping to salvage our capacity for knowledge.
Fallibilism
This approach accepts that certain knowledge is out of reach, but maintains that we can have justified beliefs that are likely to be true.
Pragmatism
Pragmatism circumvents sceptical doubts by defining truth in terms of practical consequences and consistency within our web of beliefs.
Contextualism
Contextualism offers a nuanced response, suggesting that the standards for knowledge depend on the context, allowing us to claim knowledge in everyday contexts but acknowledging the force of sceptical arguments in philosophical discussions.
FAQ
The regress problem is a sceptical issue that arises in the context of providing justification for our beliefs. According to the problem, any given reason for a belief requires a further reason, which in turn requires its own justification, leading to an infinite regress. If this regress cannot be stopped, it seems that we have no firm foundation for our beliefs, rendering all knowledge unjustified. Sceptics use this problem to argue that if there are no basic beliefs that can halt the regress without themselves requiring justification, then it appears that we have no justified beliefs at all. This sceptical argument thus challenges the coherence of our belief systems and the possibility of having any justified knowledge, contributing significantly to sceptical thought by questioning the structure and foundation of epistemic justification.
The Gettier problem is a challenge to the classical definition of knowledge as justified true belief, introduced by Edmund Gettier in 1963. Gettier presented cases in which a person has a belief that is both true and well-supported by evidence (justified), yet intuitively does not seem to be knowledge. This problem is significant for discussions of scepticism because it demonstrates that having a justified true belief may not be sufficient for having knowledge. The Gettier problem thus feeds into sceptical discussions by revealing potential flaws in our understanding of knowledge and by suggesting that our criteria for knowledge might be incomplete or incorrect. It compels philosophers to refine the definition of knowledge and to investigate more deeply what it means for a belief to be justified, ultimately enriching sceptical and epistemological discourse.
The 'brain in a vat' hypothesis is a modern thought experiment related to scepticism, particularly to arguments concerning the external world and our knowledge of it. It posits a scenario in which a human brain is kept alive in a vat and connected to a computer simulation that provides it with the same experiences that it would have if it were in a skull, and the person whose brain it is had a normal perceptual experience. This thought experiment serves to question the reliability of our perceptions and the possibility that our entire experience of the world may be an elaborate illusion. It is related to sceptical arguments that challenge the assumption that our cognitive faculties provide us with direct knowledge of an external world, thereby highlighting the limits of our knowledge and the need for a strong foundation for epistemological claims.
Cartesian scepticism, as proposed by René Descartes, is methodological, employed as a strategic doubt at the outset of his philosophical enquiries to establish certain, indubitable truths. Descartes doubted everything he could, including the evidence of the senses and the existence of the physical world, to find an absolutely certain foundation for knowledge, famously arriving at the cogito, "I think, therefore I am." Pyrrhonian scepticism, named after Pyrrho of Elis, is more radical and practical, aiming to suspend judgement on all matters to attain a state of tranquillity (ataraxia). Pyrrhonists refrain from making claims about the reality beyond appearances, remaining uncommitted to any knowledge claims to avoid the unease that comes from trying to discern the true nature of things.
Scepticism can indeed be considered a valid and influential philosophical position. It is not merely a paradox; it represents a critical approach in philosophy that challenges the very possibility of certain knowledge. While scepticism raises questions that may seem paradoxical, such as suggesting we cannot know anything with certainty, it also encourages the thorough examination of our assumptions and beliefs about knowledge. The enduring discussions around scepticism demonstrate its value in philosophical discourse. It forces philosophers to confront the foundational issues of epistemology and develop more robust theories in response to sceptical challenges. As such, scepticism is an integral part of philosophical enquiry, as it pushes the boundaries of what is considered knowable and helps refine our understanding of truth, belief, and justification.
Practice Questions
The argument from illusion plays a pivotal role in sceptical claims by challenging the reliability of sensory perception as a source of knowledge about the external world. It asserts that since our senses can deceive us, as when a stick appears bent in water, we cannot trust them to provide us with direct knowledge of the way things truly are. An excellent response to this argument acknowledges its potency in revealing the fallibility of perception but also critiques it by exploring responses such as direct realism or representational theories of perception, which aim to reconcile common-sense beliefs with the possibility of sensory deception.
Moore's common sense response effectively counters external world scepticism by asserting that everyday beliefs are more certain than sceptical hypotheses. By claiming to know hands exist when he sees and moves them, Moore demonstrates that certain basic beliefs—held with conviction—cannot be easily dismissed by sceptical doubt. However, this approach has been critiqued for its apparent circularity, as it assumes the existence of the external world to prove that very point. Despite this, an excellent response appreciates that Moore's appeal to what 'seems evident' offers a pragmatic way to bypass elaborate sceptical scenarios, reinstating our trust in sensory experience as a generally reliable source of knowledge.
George studied undergraduate and masters degrees in Classics and Philosophy at Oxford, as well as spending time at Yale. He specialises in helping students with UK and US university applications, including Oxbridge and the Ivy League. He writes extensively on education including on schools, universities, and pedagogy.