A Very Short Introduction to David Hume
What is the aim of this short article? During a lecture at the KU Leuven in Belgium, professor Roland Breeur, recommended Dr. Patricia de Martelaere as ‘an excellent introduction’ to David Hume. “At least, for those who can read and understand Dutch.” Since I do, I decided to give it a go and found myself pretty soon in agreement with the professor.
Martelaere’s combination of clarity and depth is remarkable. This is why I decided to translate (or rather, rewrite) my Dutch notes into English so that a broader audience (including students in my class) could read her clear introduction to Hume’s epistemology.
Chapter II, David Hume Filosoof van de menselijke natuur, 2001,
Van scepticisme tot naturalisme
Introduction
Hume’s philosophy is widely known to include certain themes such as the impossibility to prove the external world, the notion that causal reasoning is not objective but based on habit, and the claim that ‘the science of human nature’ is the most fundamental science.
These sceptical themes should not be understood to imply that our usual way of thinking, our day-to-day thinking is not reliable. It is reliable for practical purposes, even though we cannot provide it with an epistemological foundation. What is more, his scepticism did not preclude the value of science and its superiority vis-à-vis other methods of acquiring beliefs (e.g. superstition). An important reason for his scepticism can be derived from his ideas concerning reason or reasonableness. Reason is not autonomous, but is best conceived as a sort of instinct that is adapted organically to the environment in which it operates. This makes Hume a naturalistic philosopher and an intellectual predecessor to Darwin.
Purpose of the chapter
Martelare’s aim is threefold. First, she wants to explicate the interwovenness of Hume’s scepticism with his empirical and naturalistic presuppositions and assumptions. Second, she wants to argue that Hume’s scepticism is reconcilable with critical scientific practice, through Hume’s “general rule” which presupposes our ability to reflexively correct our natural instincts. Third, Martelaere wants to compare Hume’s thinking with Popper, considering them similar but concerned with different norms of reasonableness.
The perceptions and their source
Hume believed that we ought to shift from our emphasis of natural sciences towards ‘a science of human nature.’ Our mental data[1] consist of “whatever can present itself to the mind”, which are called perceptions. There are three sources of perceptions: sensing, having passions, and reflecting. Hume’s main method consists of trying to understand their interdependent[2] causal relationships. This methods concerns questions such as: which perception is the most fundamental, how are other perceptions derived from this fundamental perception, how are these complex perceptions built from less complex ones?
The first distinction within the perceptual order of things is based on the liveliness (or vivacity) of perceptions. There are two fundamental kinds of perceptions: impressions and ideas. All impressions and ideas are assigned a certain level of liveliness which is not characterized by stability or unambiguity. Rather, it is a contingent and guiding factor which can only be “felt”[3] dependent on supplementary circumstantial factors.[4] All of this means that the perceptual status[5] of a certain perception can shift based on the level of liveliness it has been assigned to, which is, as stated above, contingent upon circumstantial factors. Some impressions or weak ideas can become, after being assigned a higher level of liveliness, ideas which are believed by individuals to be true. Ideas include objects of expectation, belief, or conviction. Since ideas are the very building blocks of our knowledge, this bias in favour of mental items which induce a certain level of liveliness in us, is a problem for the rational status of thought. After all, not only reasonable ideas can become lively, but also fictional ones, including illusions and any other random idea. This problem all the more worse if we consider that there is hardly any other criterion for judging the veracity of an idea.
The only things which are indubitable in the human mind are perceptions and the manner in which they occur to us. This implies a rejection of representationism which considers perceptions to have some sort of relationship with external objects. Hence, for Hume, consciousness is an internal phenomenon.[6] This means that the justification of human claims of knowledge based on external objects are excluded from the outset. However, the human capacity to know is not altogether impossible, since human knowledge can pertain to certain practical matters without having to claim anything in metaphysical or ultimately correspondential terms.
The main focus of Hume is hence not to find an ultimate justification for the practice of knowledge claims, but concerns itself rather with the complex mechanisms that play a role in how our claims to knowledge come to exist in the first place. For Hume, then, “factually existing things” come to be understood as things to which we assign liveliness, and existent things as entities that include all our impressions qua impressions.
Senses and the imagination
Hume divides the senses into two domains, the first domain and the second one which is responsible for the imagination. The imagination is a faculty that can reach towards infinity and can align itself with the sensory data, while also being able to break all the laws it supposedly contains. This possibility of either aligning or non-aligning of the imagination with the senses in the first domain allows for a certain method of confirmation in Hume’s thinking. This method is predicated on the assumption that all non-fictious ideas can be traced back to their origin as sensory (complex or simple) data. Whenever this is not possible, it is fair to assume that this idea is fictious, which is a weapon Hume uses against what he considers to be the pseudo-ideas of metaphysics.
The memory is seen as reliable, except in so far as there is pollution from the imagination. The difference between sensation and memory is in the level of liveliness (or vivacity). The great importance of memory, for Hume, does not concern the nature of sensory date but the relationships one can form between these data. The sense perception only provides us with contiguity and succession of different perceptions. However, the memory, which presides over a longer period of time, is capable of comparing different perceptions with each other and to form a relationship of resemblance. With this relationship and the opportunity to compare, we start to compile human knowledge and initiate the attainment of reasonableness.
The differences between the imagination and the memory are twofold: liveliness (generally lower for imagination) and the fact that imagination is not bound to a succession of perception in the same way perceptions are.
Imagination has two different usages in Hume. Imagination in the broad sense is the ability to form “images” or weaker ideas. These include the human reason and comprehension. In the narrow sense, imagination (or fancy) is in some sense the opposite of reason, as it is led by completely random, chaotic, and fantastical connections and ideas.
Despite the fact that the imagination is free in principle, it is partially kept in check through the constant ways in which ideas form relationships with each other. There are three categories of such association principles: resemblance, contiguity, and causality which do not hold the statute of necessary or forceful law-like rules. What is more, these connections can come to be disconnected. Despite this contingency, these are considered to give some sense of reliability and “reasonableness” to our concatenation of ideas, without which the imagination would consist of a mere whimsical phantasy.
There is, however, a danger to this association, since these associations can be formed erroneously which means, in this case, that they are created as a result of a discrepancy between an intended connection and the resulting connection. Imagine that we want to connect an idea 1A with an idea 2A, but we erroneously connect 1A to the proximate but incorrect 2B.[7]
What should be kept in mind is that the associations themselves are not assigned an empirical source/cause as these associations themselves do not arise from experience. In addition to these natural non-conscious processes of relationship formation, we can have philosophical relationships which pertain to the conscious comparison of ideas and the foundation of all human reasoning. Whatever falls outside of the realm of application of the association can be considered, as was alluded above, as fiction. That is, any complex idea whose content cannot be traced back to a corresponding complex impression, such as a Pegasus.
The inner-workings of human knowledge
The imagination is either random or is structured by the principles of (natural and non-conscious) principles of association. These principles of association, in turn, can be used to form philosophical relationships which are said to be the basis of each kind of reasoning.
These philosophical relationships can be divided into two forms. The first are relationships which are completely dependent on ideas which are compared and exist a priori and necessarily. Think of mathematical or geometrical relationships. These are necessary and unchangeable. The second set of relationships are relationships of probability. These are created through the comparison of ideas and the addition of experience (including impressions). In this latter set, the causal relationships are central as they confirm the existence of things which are not immediately given to the senses. This is this realm in which natural sciences operate.
The problem that Hume detects is that while the inferences from observations to principles are crucial to the sciences (e.g. all the swans I have seen are black, hence all swans are black)[8], they are not justifiable in terms of necessary relationships (e.g. mathematics) or relationships of probability, since the occurrence of something in the past does not prove that there is a universal principle, let alone that there is a principle which will stretch into the future.
In this sense, our inferences are not justified in terms of reason and hence rely on our sense impressions and the kind of feelings they invoke in us. This removes logic from our scientific approach and reduces our inferences to basic psychological structures which we share with animals.
In the final section of this chapter, Martelaere proceeds to show what Hume’s philosophy of science is and how this compares to Karl Popper’s. Please try to get a hold of the book to read the rest of this chapter or other chapters. The Dutch title is as follows: Patricia de Martelaere, Willem Lemmens (red.), David Hume, Monografieën, Pelckmans — Agora. The ISBN connected to the Belgian publisher is: 90 289 2813 8, the Dutch publisher’s is: 90 391 0802 1. It might also be helpful to request an English translation from the publisher and help to get this collection of knowledge and expertise out of obscurity.
Disclaimer: I have written this summary based on the Dutch notes of the chapter in my notebook. I am fully aware that I might have made some mistakes along the way. Please feel free to contact me if this is the case, you can do so through the following link: www.fascina.nl/contact
You can get David Hume’s “An Enquiry into Human Understanding” here, you can get “A Treatise of Human Nature” here, and you can get this specific book at your library (probably only in the Netherlands or Belgium).
Notes:
[1] Dutch: Gegevens
[2] Dutch: Onderlinge. Can be translated as “mutual”.
[3] Dutch: Aangevoeld
[4] Dutch: Bijkomende omstandigheden.
[5] Dutch: Statuut.
[6] Dutch: is gesloten.
[7] My own interpretation of what Marteleare means.
[8] My own example.
