A brief epistemic history of Western thought (part 2): Reality and Knowledge

The story of Philosophy from Descartes to today

In the first part of our rapid overview of the history of Western thought centred around the epistemic attitudes at play, we started with the Socratic Challenge: how can we prove that we know more than nothing? Or to put it in the terms we adopted there, how can we justify a principled epistemic confidence and prove Socrates (and other philosophical skeptics) wrong?

The first part took us up to the 1600s with three different responses to the collapse of the Medieval synthesis, each of which, to simplify, lead to different traditions within Western thought. From the 1600s onwards, core philosophical discussion of reality and knowledge, scientific investigation of the natural world and ‘applied’ philosophy (i.e. politics, ethics etc) increasingly split into different debates.

This next installment will examine the core philosophical tradition, focused on reality and knowledge, as it has grappled most explicitly with the Socratic Challenge. This tradition is often attributed to the influence of Rene Descartes. As argued previously, he “set out to regain epistemic confidence through a new philosophical approach and is now known for Cartesian skepticism.” Much of modern philosophy since has been a response to Descartes, whether explicitly or implicitly, and an attempt to escape Cartesian skepticism.

The core challenge is to prove, or establish with deep confidence, that we know the types of things that we think we do about the world and humans. As such, it is an updated form of the Socratic Challenge, just with the odds raised. Descartes provided a strong argument that we couldn’t justify any of the things we think we know, including the existence of the world around us.

This provides a neat, if necessarily simplified, framework for a rapid survey of the history of philosophy since Descartes. Most notable philosophers attempted to ground epistemic confidence or certainty in various ways, with the attempts getting more creative as time went on. Some embraced elements of Cartesian skepticism, either fully or in part.

This lightning fast tour through the canon of Western philosophers will aim to summarise each philosopher's key insights, explain how it attempted to create the missing confidence and quickly evaluate where it succeeded or failed. This approach will unavoidably leave out almost all nuance and much of what made different philosophers justifiably famous. The aim is to follow the larger pattern.

Descartes to Kant

Those immediately following Descartes largely adhered to the traditional methods of philosophy: careful reasoning about our experiences and the world to try to identify a holistic account that justified reality and knowledge and avoided skepticism. Like the Ancient Greeks and Medieval thinkers, human reason was presumed to be sufficient to establish a philosophy with certainty, or at least the core elements of it.

John Locke responded to skepticism by seeking to establish the limits to human understanding, or what we could know. His argument was that philosophers, like Descartes, ended up in skepticism as they ‘extended their Enquiries beyond their Capacities’. As such, Locke stepped away from a complete epistemic confidence - as there are things humans cannot know. While the Medieval thinkers thought that Revelation established boundaries on what humans could know, Locke assumed that human capacities were sufficient to establish the boundaries on human capacities. This allows him to confidently establish limits to understanding and means that he had a high degree of epistemic confidence within those limits.

Locke’s philosophy was empiricist as he argued that the human mind is born as a ‘blank slate’ and all knowledge is derived from our experiences. He gives a detailed and interesting account of how that occurs, although many continue to critique it. Ultimately though, his account struggles on the point that also tripped Descartes over: how can we be sure that our sensations and experiences are of real things?

While Locke took an explicitly empiricist approach, Gottfried Leibniz took a more mathematical approach that started with core principles of logic. He saw these principles, especially the Principle of Contradiction (something can’t be both true and false) as the foundation of human knowledge and therefore philosophy. In his view, all these Principles were necessarily true. Therefore, by building out a philosophy and epistemology based on them, he would - in our words - establish epistemic certainty. While brilliantly constructed, his emphasis on internal logical rationality lead him to an elaborate ontology where the only entities that genuinely exist are simple, mind-like substances he called monads. This has been entirely unconvincing for most people. Leibniz worked to create epistemic confidence, but ended up with a system that doesn’t seem to describe the universe we inhabit.

George Berkeley built a less intricate philosophical system than Locke or Leibniz. His core response to Cartesian skepticism was to argue that the typical assumption that there is an independently existing material world is flawed. Instead, everything that exists, exists because it is perceived - esse est percipi. As such, reality is mind-dependent. As befitting his position as Bishop of Cloyne, Berkeley developed his account into an argument for the existence of an infinite and good God, as that is necessary to unify diverse mind-dependent experiences into a coherent world. Similar to Descartes’ approach, the existence of God gave us confidence about the reliability of our knowledge. This confidence, however, only makes sense within his ontology, or view of reality, and that depends on a number of key assumptions that very few people accept.

David Hume addressed a range of traditional philosophical problems by investigating human nature and showing how we come to believe core ideas, rather than trying to demonstrate they are true. To achieve this, he extended Cartesian like skepticism to cover topics like causation and personal identity. For example, Hume argued that we can never prove that one things causes another and, instead, focused his analysis on explaining why humans think that causation exists.

On many traditional philosophical questions, this is an expression of epistemic skepticism - we cannot know the answers. As such, Hume deepened the challenge of Cartesian skepticism as he expanded the range of phenomena we could (and even should) doubt. However, for Hume, this didn’t matter that we couldn’t answer these questions. It was far better for us to rely on ‘the ordinary wisdom of nature’.

On other questions, Hume proposed a thorough empiricist system built on human nature and how we act. The hope was that this would provide us with epistemic confidence about the topics for which we needed it. However, Hume’s skeptical arguments remain much more famous than his positive program and for good reason. To take one example, his view that causation is really only a human custom by which we associate different events leads us to question whether we can ever rely on causal explanations. It does not provide a strong basis for scientific inquiry.

Immanuel Kant famously said he was ‘woken from his dogmatic slumber’ by Hume’s writing and, in some ways, the structure of what he tried to achieve was similar to Hume and even Locke. Like these British empiricists, Kant first tried to establish the limits on human reason and knowledge. Rather than tying it to our experiences, Kant argued that we are fundamentally limited by the way that we, as humans, are. We do not experience objects (or the world) as they are ‘in themselves’. We can only know them as we experience them. To take an example, space and time are structures of how we experience the world, and don’t belong to ‘things in themselves’. To invoke an obvious metaphor, we cannot see objects as God sees them - we are restricted to seeing them as we humans do.

While this is traditionally taken to be an ontological claim by Kant (who isn’t clear in his writing in many cases), I think it is fruitfully understood as an expression of epistemic humility. We can never be sure what the world is like independently of our senses and ways of experiencing the world. Moreover, Kant argues that our experience of the world is determined by ‘Categories’ - core concepts or predicates that determine how we as humans understand and experience objects. For example, Kant thought causation was a Category, that is humans cannot experience or make sense of the world without causation. Whereas Hume saw causation as a custom or habit, Kant thought it was, to use a modern analogy, hardwired into humans and we cannot avoid thinking in terms of it.

Again, like Locke and Hume, Kant started with a project of humility and skepticism - trying to define limits - and then used that to build a system that was designed to provide epistemic confidence or certainty. Kant’s political and ethical writings famously express complete confidence in the universal applicability of his principles, such as the Categorical Imperative, to all of mankind. This generalisation, without clear justification, is one of the core weaknesses in Kant’s thought. It is not clear that his extrapolation from his personal and internal observations works universally.

As mentioned, all of these thinkers sought to use the careful application of human reason, often with an explicit recognition that it has limits, to resolve philosophical difficulties. Of interest, where they identified limits, these were defined in terms of content or subject matter: there were topics where human reasoning couldn’t provide answers. They didn’t subscribe to limits in what reason could establish within its proper scope. In other words, reason was presumed to provide epistemic confidence or certainty within its rightful boundaries. However, none of them satisfactorily addressed the Socratic challenge or solved Cartesian skepticism.

After Kant, the methods of philosophy started changing as the traditional approach of applying human reason to provide a universal system was slowly abandoned. Philosophy is typically divided into two different streams, continental and analytic philosophy, that came to adopt different approaches to the search for epistemic confidence. Broadly speaking, continental philosophy tried to remain universal but looked for different sources of confidence than traditional approaches to human reason. Analytic philosophy, on the other hand, began focusing on smaller problems with an implicit confidence that these could be combined into solutions for larger challenges.

Continental philosophy after Kant

GWF Hegel took an ingenious approach to logic as a path to regain intellectual and epistemic confidence. His philosophy was based on an understanding of reasoning and logic that wasn’t deductive and analytical. Reasoning and logic for Hegel, via his famous dialectic approach, didn’t primarily analyse but produced or even created new concepts and understanding.

Put somewhat simply, human reason starts with a concept and then it naturally considers the opposite concept. However, then when you observe the movement from concept to its opposite, that produces a new concept. An example might help. One foundational concept is ‘being’ or ‘existence’. Once you think about that, you can grasp the opposite: ‘nothing’ or ‘non-existence’. Then, by connecting the two as two possibilities, you can grasp the concept of ‘becoming’ or ‘change’. This dialectic approach, for Hegel, followed a necessary logical path and all human knowledge was based on this process. Moreover, the same necessary dialectic and necessary pattern governed human and world history - therefore guaranteeing our confidence in our knowledge.

Unfortunately, not only was Hegel's writing notoriously tough to understand but his dialectic logic did not seem to actually establish many facts about humans and the world, and in the places it worked that only seemed to be with the benefit of hindsight. It was ingenious but failed to conclusively ground any epistemic confidence.

Arthur Schopenhauer was a contemporary of Hegel’s but took a very different direction. He argued that the world wasn’t inherently rational or understandable and in the place of reason he placed Will at the core of existence. Existence, experiences and the world are, for Schopenhauer, direct expressions of Will (both human and a broader universal). This approach avoids many epistemic questions but it nevertheless provides us with “an unshakeable certainty that we are the doers of our deeds.” Certainty and confidence is no longer to be found in reason, but elsewhere.

Friedrich Nietzsche also turned to will as the source of confidence or certainty but removed Schopenhauer's concept of some kind of universal will. At the heart of existence and history is a ‘will to power’. Given all the old metaphysical ideas were, on Nietzsche’s view, dead, what was now required was a complete or strong man (the Ubermensch) to impose certainty and greatness through the exercise of their personal will.

Edmund Husserl, and the phenomenologists following him, sought to ground knowledge in the structures of human consciousness within which we all represent things to ourselves, including our experiences of the world. Husserl built a rational and logical account of knowledge on these units of consciousness. Starting with something that is immediate to all of us allowed him to build his system without first resolving Cartesian skepticism about any external reality. However, it neither found a way to escape the skepticism nor could prove that the intuitions on which it is based validly generalise to all people. An attempt at epistemic confidence based on the immediate structures of consciousness remained subjective and therefore uncertain.

Leaving aside the debates about who is an existentialist, this school of thought (associated definitely with Jean-Paul Sartre) placed existence, intentional choice and authenticity at the heart of philosophy - with pre-reflective intuitions as the basis for much of what we can trust we know. There is no pre-existing purpose or structure for humans and therefore confidence could be found by creating meaning through free choice. Again, the confidence this created might have been intuitively powerful but was fragile whenever anyone tried to make it universal.

The clear trends towards the individual - whether via the structure of consciousness or will or choice - in many ways coalesced in post-modern and deconstructionist philosophies. This approach, championed by Habermas, Foucault, Lyotard, Derrida and others, accepted Cartesian skepticism to a large degree. For them there are no meta-narratives or grand truths about what the world is like. Instead, to simplify, each individual creates their own meanings in reacting to texts (one of which is the external world). This allows for a certain degree of personal confidence at the expense of a broader epistemic skepticism. However, as seen in a previous post, this way of thinking has evolved rapidly into an expression of profound epistemic confidence based on moral concepts.

As a tradition, Continental philosophy since Kant has tried to ground confidence and certainty in concepts or faculties apart from human reason and direct experiences. While each of these have provided insights about humans and the world, the fact that the natural end point was a post-modern rejection of Truth demonstrates the ways these failed to established any epistemic confidence, let along certainty.

Analytic philosophy after Kant

While the Continental tradition tended to respond to Cartesian skepticism and the Socratic challenge by turning inwards - focusing on will, consciousness and choice - a second tradition emerged that increasingly started with other areas of knowledge and science. Of particular note is that it adopted the reductionist approach used in most areas of science. That is, to understand issues, you break them down into smaller ones, solve the smaller issues and then amalgamate all of those into the bigger picture again. Analytic philosophy is now primarily associated with English language philosophy. We will just skim a few key figures.

Gottlob Frege was focused on trying to formally understand reasoning, mathematics and concepts. In order to do so, he established the modern approach to logic and formal languages. He, but also Bertrand Russell and Ludwig Wittgenstein (at least initially) saw this formal approach - and the formal language it provided - as the basis on which knowledge and certainty could be grounded. This set the template for a careful examination of logic, concepts and definitions within analytic philosophy. While their approach was powerful mathematically, they could never escape the formalism to describe the real world with any certainty and were permanently stuck in a type of solipsism.

In response to this weakness, the logical empiricists (associated with the Vienna Circle and AJ Ayer) divided knowledge into the purely formal - like logic and mathematics - and that which provided information about the world. These latter questions were considered to be scientific and were only meaningful if they could be empirically testable or verifiable. This philosophy drew on the methods and authority of scientific approaches as the ground for epistemic confidence. While it is a framework that continues to have influence today, philosophically it largely begs the question. It assumes that modern science gives us epistemic confidence and then provides an account of how that works.

Wittgenstein himself took a different response to the weaknesses in his early work. In an echo of Hume’s attitude, Wittgenstein’s later philosophy saw philosophical questions as essentially confusions about language. It was the role of the philosopher to clear up these puzzles that didn’t really exist. As such, his attitude was that philosophy was a form of therapy. Unfortunately, this therapy did not quiet the doubts or concerns of philosophers.

The methods of more recent analytic philosophers, of which there are many but none with broad public name recognition, draw on these approaches. They focus closely on logical structures and precise definitions of relevant concepts, typically assume that scientific knowledge is reliable (or gives us confidence) and focus on the way we use concepts in ordinary language as evidence or a touchstone for their thinking. A unifying approach is a strong focus on resolving philosophical problems from the bottom up. They focus on solving a series of small technical philosophical problems and with the assumption that solutions to broader issues will follow.

While there are many benefits to the focus on careful precision, modern analytic philosophy has clarified many debates but resolved none. Despite a clear drive for a epistemic confidence grounded in precise conceptual analysis and definitions, none has been achieved. For philosophy as a discipline, epistemic confidence is no closer than it was at the time of Descartes.

What can we learn?

The history of Western philosophical thinking that has been sketched is, as a response to the Socratic Challenge or Cartesian skepticism, a series of brilliant failures. There have been many sophisticated thinkers with brilliant and arresting ideas, but we still can’t be certain that the world exists or that we know anything.

A simple, but counter-intuitive for many, conclusion from this is that our goal has been wrong. Intellectual certainty about our knowledge and basic things like the definitive existence of the world is a false hope. Doubts are always possible and cannot be definitively ruled out. The solution is not to try and remove doubt but recognise it is a fundamental part of existence and knowledge. Knowledge is hard. We get things wrong, even very foundational things.

In other words, the history of philosophy is a long argument for epistemic humility. As hard as we try, we cannot definitively solve a series of fundamental questions. In response, we should perhaps accept the uncertainty and work with it. Some other traditions of thought, including scientific methods, have done so and been successful. That is a story for a later post.