By Douglas Anele
According to A. C. Grayling, “In both the ordinary and philosophical senses, a sceptic is one who, at least unless he is shown satisfactory reason why he should do otherwise, doubts some proposition, belief or theory.” This implies that the word ‘scepticism’ connotes ‘doubting,’ ‘questioning,’ and ‘unwillingness to accept a claim without sufficient evidence to back it.’ But etymologically speaking, ‘scepticism’ can be traced to the Greek expression skeptikos or skepsis, which means ‘inquirers.’ Simon Blackburn affirms that although scepticism in ancient Greece focused on the value of inquiry and questioning, nowadays it is usually understood as “the denial that knowledge or even rational belief is possible, either about some specific subject-matter (eg. ethics) or in any area whatsoever.” There is no doubt that humans are fallible beings and that the possibility of error in claims to knowledge no matter its source or inspiration can never be completely ruled out. In classical western philosophy, scepticism emerged from the realisation that the most reliable methods for acquiring knowledge often do not guarantee truth or certainty since, inter alia, appearance is not necessarily identical with reality. Moreover, these methods often lead to conflicting judgments, with the result that the question of truth becomes undecidable sometimes. From experience, it cannot be denied that what seems to be real and that which is really real are often different. The lacuna between what really is and what appears to be coupled with the fact that reality is in a state of flux led several ancient Greek philosophers such as Heraclitus, Cratylus and Xenophanes to doubt the very possibility of knowing anything. From the time of these thinkers till date, scepticism has been espoused in various degrees by different philosophers such that it is fair to assert that, like every school of thought or perspective in philosophy, each proponent of the sceptical attitude can be described broadly as either moderate or extremist, as the case may be.
As a systematic critical stance with respect to knowledge claims, scepticism has remained a constant feature of philosophy right from its evolution in antiquity. As indicated earlier, a number of ancient Greek thinkers had already set the ball of scepticism rolling even before the iconic triumvirate of Greek philosophy – Socrates, Plato, and Aristotle – made their mark in philosophy. Two of them, Gorgias and Protagoras, could be described as extreme sceptics. Gorgias reportedly doubted whether anything exists, and insisted further that if anything existed at all it cannot be known, and that even if it is known it cannot be communicated. On his part Protagoras, a sophist, claimed that “man is the measure of all things, of the things that are that they are, and of the things that are not that they are not.” Also notable is the brand of scepticism taught by leaders of Plato’s Academy, particularly Arcesilaus and Carneades. Members of this school, having turned their backs on Plato’s metaphysical and mystical teachings, adopted Socrates’ questioning method and focused on working out the implications of the Socratic claim that “All that I know is that I know nothing.”
An interesting influential school of scepticism known as the Pyrrhonian School emerged during the Roman period. The leading ideas of members of this school can be traced to the views of Pyrrho of Elis (c. 365-275B.C.). Taking a principled position against dogmatism, Pyrrhonism encouraged the refusal to accept the testimony of the senses. A strand of the Pyrrhonian School accepted the phenomena or appearance of things together with the customs and moral standards of the society one belongs to, but doubted unnecessary speculations especially about unobservable realities. In addition, Pyrrhonists argued that since epistemological investigations tend to be frustrating and unproductive because of the difficulty in deciding whether the reasons for accepting any proposition are better or worse than those against it, one should suspend judgement in order to experience ataraxia (or peace of mind). Sextus Empiricus, one of the ablest Pyrrhonians, developed a method of sceptical argumentation that leads to epoché (suspension of judgement) about issues concerning what is not evident.
During the Middle Ages, St. Augustine’s Contra Academicos, which was an attempt to respond to the scepticism of the Academicians, represented the Christian discourse on scepticism. Al-Ghazali and Yehuda Halevi, Muslim and Jewish theologian respectively, not only criticised Aristotelians of the medieval period but also questioned the very possibility of rational scientific and theological knowledge about the real nature of the cosmos. But unlike their ancient Greek counterparts who were primarily motivated by the desire to delineate the cartography of certain indubitable knowledge, if at all that is possible, Arabic and Jewish sceptics were more interested in projecting a mystical and non-rational engagement with religious truths by displaying the intellectual bankruptcy of the so-called rational theologies prevalent at that time (ibid, 451). Yet the mystical non-rational perspective suffers from a worse defect than the rational theologies al-Ghazali and others criticised because of its extreme subjectivity and decoupling from reason and empirical evidence.
At the beginning of the renaissance period, the Academic sceptics and their Pyrrhonian counterparts focused mainly on theological controversies. For instance Erasmus, in his work, in Praise of Folly, ridiculed some scholastics for their endless, epistemologically barren, theological disputations. In De Libero Arbitrio he criticized Martin Luther and pointed out that the question of free will was too complicated for humans to comprehend and that scriptural interpretations cannot resolve the problem. Michel de Montaigne, the patron-saint of scepticism in sixteenth century France, set the stage for the problems of modern philosophy. Montaigne underscored the difficulties of judging the reliability of sense perception, adding that idiosyncratic, social, and cultural factors play an important part in the manner people interpret reality. He even argued that the criteria used in determining standards of judgement themselves are open to doubt “unless God gives us some indubitable first principles and makes our faculties reliable.” The writings of sceptics like Erasmus, Sextus Empiricus, Montaigne, and Pierre Gissendi provided the background for René Descartes’ version of scepticism. Descartes claimed that by deploying the methodic doubt more rigorously than sceptics before him had, one can discover indubitable standard for true knowledge which leads to rationally interlocking truths about reality. In other words, the Cartesian approach begins with scepticism, applies it to discover the foundation of certain knowledge (cogito ego sum), and then stretches it further to distil indubitable metaphysical knowledge from clear and distinct ideas. However, critics correctly doubted whether the cogito proved anything at all, and whether it could serve as a solid foundation for knowledge. As Gassendi, one of Descartes’ contemporaries observed, what Descartes thought to be indubitable truths might actually be a subjective worldview in his mind and not a true representation of reality.
The major works of David Hume and Immanuel Kant contain significant sceptical conclusions. In A Treatise of Human Nature and Enquiry Concerning Human Understanding, Hume maintained that no truths about matters of fact can be proved deductively or inductively. Moreover, the notions of “uniformity of nature” and “necessary connection” which underpin induction cannot be established since the evidence for them are inconclusive. In the last chapter of the Enquiry and Dialogues Concerning Natural Religion, Hume raised doubts concerning the trustworthiness of rational and empirical reasoning in philosophy and theology, and questioned the reasons philosophers had advanced for belief in the existence of an external world, the self, and God. It is interesting to note that Hume recognised that his extreme scepticism is unsuitable for practical living, which is an indirect acknowledgement that scepticism taken too far is unrealistic and unsustainable. On his part Kant, having assumed that scientific knowledge is possible, tried really hard to respond to the sceptical conclusions of Hume as regards the very possibility of knowing reality. The result was his magnum opus, Critique of Pure Reason. The key problem, for Kant, is to provide a convincing account specifying the conditions for all possible experience. He believed that he had met Hume’s sceptical challenge with his own version of the Copernican revolution. Kant held that knowledge begins with experience, but does not arise from it. He maintained that the categories of human understanding (such as causality, space, and time), and the logical forms of judgement are the conditions for all knowledge about the phenomenal world, that is, the world as it appears to us as human beings. Nevertheless, the categories and logical forms are not applicable to the noumenal world, the world of things-in-themselves, which comprises the actual contents of experience, the self and God. The fundamental limitations of Kant’s analysis of knowledge were not lost on other philosophers shortly after his critical philosophy was published. For example, G. E. Schultze insisted that Kant did not resolve Hume’s scepticism which woke him (Kant) from dogmatic slumbers because of his failure to go beyond the subjective preconditions for the possibility of experience to any objective or subject-independent claim about reality. Another critic, Salomon Maimon, agreed with Kant on the reality of the a priori categories or concepts necessary for knowledge, but maintained that their applicability to experience depends on inductions from experience whose validation is purely a matter of probability, not certainty. Interestingly, a theologian, Johann Georg Hamann, used the sceptical arguments of Hume and Kant to launch his antirational fideism, the doctrine that knowledge depends on faith rather than reason.
Now, two notable German metaphysicians, Johann Fichte and G. W. F. Hegel, attempted to avoid the sceptical submissions of Hume and Kant through a shift in focus towards creativity and the historicity of knowledge. For both philosophers, scepticism is a stage in the understanding of unfolding events that could be overcome by the creative construction of, and commitment to, an all-embracing worldview. Furthermore, although Hegel values scepticism as a movement that respects the freedom of reason, the racist, sweeping, magisterial tone of some of his views tends to promote intellectual hubris, not scepticism.
It was not too long before the speculative metaphysics of German idealists like Hegel and its incarnation in Britain by F. H. Bradley was subjected to critical fire by Bertrand Russell, G. E. Moore, and the logical positivists. The Russellian and positivist critiques included a strong anti-metaphysical component in the form of scepticism about, or outright rejection of, transcendental metaphysical knowledge. Russell, like the positivists, put premium on knowledge derived from logic, mathematics and science. Nevertheless, because scientific knowledge is probabilistic, he rejected dogmatic claims to knowledge by metaphysicians and theologians. The logical positivists and linguistic philosophers (in particular) ushered in what is often described as the linguistic turn in philosophy. Deploying different strategies, these philosophers attempted to circumvent the perennial problems of scepticism by positing that knowledge properly so-called is restricted to logically true propositions, empirically verifiable facts, and commonsense assertions and beliefs. The positivist move from hardnosed idealism to science, mathematics and commonsense seems reasonable. Yet, as critics such as Karl Popper have observed, the positivist verifiability principle cannot serve the dual purpose for which it was formulated in the first instance, whereas the quest for indubitable empirical foundation for science or knowledge generally is misguided and cannot be fulfilled. Linguistic philosophers have been accused of deviating from the interesting problems that oxygenate philosophy through “excessive concern with the contours of everyday linguistic usage characteristic of some philosophers at Oxford in the years following the Second World War.”
Popper himself can be justly described as a moderate sceptic. He insisted that although the aim of science is truth, there is no guarantee that any scientific hypothesis can be shown to be true due to the ever present possibility of falsification. Aside from that Popper, unlike the foundationists, rejected the notion that science can be grounded on a solid epistemological bedrock. He emphasised the dynamic, fallible and progressive character of knowledge. Popper’s thoroughgoing rejection of induction has been shown to be unsuccessful on the ground that his advice that scientists should work with the best corroborated hypothesis is inductive in nature.
In contemporary times, disillusionment with the idea of the inevitability of progress and the collapse of hopes for peace, justice and happiness across the world (which are some of the far-reaching outcomes of the two world wars), increasing global socio-economic challenges and political upheavals, not to talk of the worsening climate disruptions and threat of nuclear war, have compelled many intellectuals to express serious scepticism about humanity’s capacity to really comprehend the world, and about the significance and value of the ideals that have guided humans since they evolved as a distinct species.
•Anele is Professor of Philosophy, University of Lagos, Akoka