Book 1. Hume’s Problems with Induction
Chapter 4. The psychology of induction
Hume tried his best to do away with the science of induction by psychologizing our understanding of it. Of course, there is a psychology of induction, since humans have a psyche and induce. But Hume attempted to reduce induction to psychological mechanisms, i.e. to substitute a psychology of inductive thought for the logic of inductive thought. He proposed a description that effectively eliminated the possibility of evaluation and prescription. He sought to permanently undercut all attempts to validate induction.
With this goal in mind, Hume proposed a psychological theory of generalization. Generalization was to him a mere quasi-mechanical or instinctive reaction of expectation due to repeated imprints in the mind; it was, effectively, an acquired habit. Essentially, Hume was arguing that the repeated experience of cases of X that are Y drives us to conclude that all X are Y (i.e. to expect that yet unseen cases will conform to past experience), even though in principle things might well (and often do) turn out otherwise.
But according to inductive logic, Hume’s theory is just a hypothesis that has to, itself (like all hypotheses), be confirmed repeatedly and never infirmed. Hume cannot regard it as somehow exempt from or transcending inductive logic. It is subsumed by it like any other theory. In fact, there is no psychological drive such as Hume projects – and his theory is itself proof of that, since he himself is aware that things might (and often do) turn out differently than expected.
It is important to notice that, in practice, while we do frequently generalize, we often do so tentatively fully aware that we might have reason to change our minds later on. Moreover, we often abstain from generalizing, because we do not want to proceed hastily or because we are already aware of contrary evidence. Also, we often particularize after having generalized, due to coming across new evidence to the contrary.
It follows from such simple considerations that Hume’s claim to a psychological law is empirically inaccurate. It is a false observation, an overly hasty generalization from limited or selective introspection. Not only does it not explain the phenomenon of generalization, nor replace the need for a logical and epistemological treatment of the issue, it is an erroneous psychological claim, incorrect psychology.
Another attempt at reductive psychologizing was Hume’s attempt to write-off causation as mere association of ideas. Basically, this suggests, Hume had personal difficulty distinguishing the fact of causation from our way to knowledge of causation; because he confused the two issues, he tried to conflate them.
Underlying Hume’s notion of association of ideas was of course his belief that what we perceive (when we seem to perceive the world) are not things in the world out there but images of such things produced in the mind through sensations. Due to this erroneous (because internally inconsistent, self-contradictory) analysis of the experiential process, he seems (in some people’s eyes) to have some credibility in affirming causation as mere association of ideas.
For Hume effectively adopted John Locke’s theory of human knowledge as his starting point. This theory admittedly seems like common sense: we have senses and they obviously somehow produce images and memories in us. However, this is the basis of the worldview that has come to be called Naïve Realism (or uncritical materialism). It seems reasonable, but upon reflection it is found to be wobbly.
If the senses truly produce images in our minds of the world beyond them, it follows that we have no direct knowledge of the world out there at all, but only knowledge of the said images (this term here intends all phenomenal modalities, i.e. not only sights, but also sounds, smells, tastes, and various touch sensations). In that case, how do we know of the bodily senses at all, and on what basis could we at all affirm a world beyond them? It is a seemingly inextricable dilemma.
At first glance, to affirm that our cognitive relation to the world out there is mediated by ideas seems innocuous. It seems obvious enough that our ideas, or most of them, somehow ‘represent’ or ‘correspond to’ the world. But upon reflection, such a view of how our knowledge is constituted and justified is logically untenable. How can we claim our ideas representative or correspondent to reality if we have no immediate contact with it by which to make this judgment? How indeed can we even claim our ideas not to represent or correspond to reality? We are seemingly doomed to utter ignorance.
To his credit, Hume (unlike Locke) became aware of the insuperable difficulty that the common sense theory of knowledge raised. Less to his credit, Hume derived a deep skepticism from this puzzle, because he effectively assumed there was no other approach. That is, rather than considering Locke’s particular theoretical approach to have caused the dilemma, he viewed the problem as a definitive cause for doubting all human knowledge as such.
That such a radical doubt in turn cast doubt on his own faculty of knowledge and conclusions apparently did not cross Hume’s mind (or not sufficiently). For, though henceforth fundamentally a skeptic, he continued seeking and claiming knowledge. But he did not try very hard to find a solution to the inherent problem. He never discovered the solution made possible by a phenomenological approach.
This approach is encapsulated by the aforementioned principle of induction, which starts the enterprise of knowledge with regard to appearances rather than to sense perceptions. ‘Appearances’ refers to the contents of consciousness irrespective of their source, so this term does not have presuppositions like ‘sense perceptions’. It is not a verbal issue, but one of ordering of knowledge, note well. In a phenomenological perspective, Locke’s theory regarding sensations and ideas is just that – one attempted explanation of certain appearances. Seen in this light, the difficulties it presents seem far less threatening.
Now, all this is said here only to explain why Hume was more or less bound to opt for a reduction of causation to ‘association of ideas’. Since his viewpoint effectively divorced ideas from their objects, he could not talk about the objects themselves without some nagging discomfort, and he was pretty well cornered into rather discussing ideas.
But it must be stressed that for us, who are free of the dilemma posed by Locke’s theory thanks to a more phenomenological approach, the scenery looks very different. We can logically distinguish ideas from the objects they intend – be these objects physical, mental or spiritual. Although ideas might conceivably always appear in certain sequences, this is not for us sufficient reason to declare the objects they intend to be causally related.
Here again, we must apply deductive and inductive standards to judge the issue.
For a start, it is worth pointing out that the concept of association of ideas is inherently one of causation. Leaving aside Hume’s view of causation as mere constant conjunction as against connection, to say that ideas are associated in some way is to claim a connection of some sort between them. If we think in terms of one idea ‘giving rise to’ another, or we use any other such expression, we are thinking causation. The implication may be tacit, but it is clearly there.
That the causal sequence concerns the specific kind of thing we call ideas, rather than the kind of thing we call objects, is irrelevant to the relation itself, which is conceived as technically the same irrespective of the kind of thing related. Causation is a certain kind of relation between terms or theses, which has nothing to do with their actual contents.
To say that the idea of X causes the idea of Y is as much a claim to causation as to say that X causes Y. The formal proof is that we can call “the idea of X” a special case of X, and “the idea of Y” a special case of Y. In formal logic, X and Y are symbols for any two terms; they are not reserved for objects as against ideas. For this reason, the principles developed with regard to X and Y are universal.
If we formally admit a causative relation between ideas (or impressions, sensations, concepts, beliefs, thoughts, or any such mental phenomena), there is no reason for us not to admit a causative relation between other kinds of things (i.e. between non-ideas, viz. the objects of most ideas). To accept the one and refuse the other, as Hume does, can only be arbitrary, for there is nothing to formally distinguish the two. The variables differ, but the underlying relation between them is the same.
In short, our use of the word association in one case and causation in the other is a mere verbal embellishment. Hume’s main argument is thus based on a superficial verbal distinction. And here again, his attempt to substitute psychology for logic is implausible. The truths of logic are independent of any psychological thesis.
Secondly, Hume is incoherent when he formulates a concept of association of ideas that is meant to exclude a concept of causation between the objects the ideas refer to. Such an exclusive contrast between the two concepts commits the stolen concept fallacy. For to invalidate the association of ideas, i.e. to point out that ideas may be erroneously associated, we need to have a more objective knowledge to compare to. It is logically impossible to claim associations of ideas to be occasionally or inherently wrong, without claiming separate knowledge of the true causation between the objects concerned.
In the very act of downplaying or denying causation between objects by positing association of ideas, Hume is relying on his and our past experience that sometimes associations do not match causations. If we had no such past experiences, we could not comprehend Hume’s argument, or be convinced by it. Hume’s discourse tacitly implies his and our ability to grasp causation independently of association, i.e. that we all have access to some objective reality.
Hume is here committing the same silly error Kant would later commit when claiming that things as they really are (“in themselves”) are radically different from things as they appear. How could he know it? No one can consistently postulate a conflict between reality and appearance without having access to both. If someone accuses humans of total delusion, he forfeits all logical right to discuss the presumed ‘real’ world, for all such discussion (even hypothetically) would be self-contradictory, since it is itself a claim to some knowledge.
The critic cannot claim to be an exception to the general rule he posits. We cannot project a scenario that excludes us – but some people keep trying to! We admittedly all have some illusions sometimes; none of us are infallible – but this is a far cry from total delusion.
It should be noticed that we are well able to distinguish the two classes, i.e. ideas and objects. Hume does so in practice, though he denies our ability to do so theoretically. Indeed, how could his discourse be at all meaningful to him and us, if we could not all make the distinction? If apparent objects were truly no more than ideas, it is doubtful we could even imagine such a distinction; certainly, it would be logically self-contradictory in the way that Kant’s dichotomy later was.
Thirdly, let us consider the facts of the case in more detail. Note that we ordinarily pass no time wondering whether our ideas are repeatedly conjoined, but only concern ourselves with their objects. Moreover, we might ask whether any two ideas are ever in our actual experience constantly conjoined; the answer seems evident to me – it is no. On the other hand, many objects do seem to us constantly conjoined.
Moreover, if we introspect sufficiently, we easily notice that ideas may become associated in our minds for reasons that have nothing to do with the objects they intend. Such association is not based on constant conjunctions, but on a single coincidence. The strength of mental association is not due to statistical frequency. For instance, a certain musical tune reminds me of a certain woman, just because it happened to be playing in the restaurant where we sat the day I met her. I may well have heard the same tune a hundred times before, without any association occurring.
This means that in our common everyday experience, without reference to Hume, the conjunction of ideas and the conjunction of the objects they intend are two quite different issues. Even if we observed our ideas and found them constantly conjoined, we would not necessarily conclude that the objects they intend are causally related; we are not (most of us) that stupid. As well, we are well able to believe two objects to be causally related even while our ideas relative to these objects do not readily arise together.
It is also worth pointing out that, intuitively, we have the volitional power (often if not always) to arouse or suppress ideas, whereas we do not seem to have similar power relative to apparent objects. We can ignore objects, or forget them, but that does not wipe them out: if we look for them again they reappear or someone else might still see them. But in the case of ideas, or more precisely many memories and derived imaginations, we experience a greater power of manipulation. On this basis, we expect the associations between ideas to be more tenuous: they depend more on our will.
All such simple observations and arguments again take us to the conclusion that Hume indulged in an excessively hurried generalization, from very little introspection and reflection. He was either lazy or dishonest, focusing on the data that supported his pet theory and ignoring the data and reasoning that contradicted it. The matter is open to objective judgment – it is not my word against his: everyone can carefully consider the data and judge independently.
The philosophical sciences of logic, phenomenology, epistemology and ontology provide the blueprint and guidelines for induction. There is of course additionally the need to consider the psychology of induction, since after all induction is an activity of the human psyche. Through such a complementary study, we can better comprehend how induction actually occurs. But psychology and logic are two very different fields.
Briefly put, I would describe the psychology of induction as follows. The human soul has powers of cognition, volition and valuation. All three of these functions come into play in every inductive act. The end is cognitive; the means is volitional (combined with non-volitional elements, provided by the nervous system, mainly the brain); the motivation comes from the valuing of knowledge, or the things or events that knowledge can serve as a means to.
The relation between the said philosophical sciences (including logic) and the psychology of induction (in an individual at a given time) is that the sciences (to the extent that they are known to the person concerned and kept in mind) influence the inductive activity of the person. They do not determine it, note well, but they influence it. This relationship thus leaves room for the cognitive, volitional and value-oriented factors of induction.
If the person has a low degree of knowledge or understanding of the scientific underpinnings of induction, he or she will naturally often make errors. However, even without formal training and reflection on the issues of induction, most people do subconsciously frequently think logically and thus a lot of the time have some measure of success in their inductions. Humans, after all, have considerable natural intelligence; else they would not have survived till now. The said sciences are, after all, very recent productions of the human mind.
The root of Hume’s problem with induction is perhaps his misconception as to what ideas are. I suggest that in his mind’s eye, ideas are clouds of ‘mental stuff’ produced by sensation. These perhaps very often look like the objects that generated our sensations, but we cannot be sure of that since we have no access to such objects other than through ideas. Thus, what we actually perceive and know are only ideas. Thus, ideas are veils that separate us from reality, rather than conduits to reality.
This view is, as already pointed out, self-defeating, since it accuses also itself of ignorance and error. However, the point I want to stress here is how ideas are reified in Hume’s discourse. Because he effectively visualized ideas as atoms of mental substance, his view of human knowledge as a whole was completely distorted.
In fact, an idea is something very abstract, an intention towards some object, a relation of pointing in a certain direction, directing our attention hither, rather than a substantial entity. An idea is an idea of an object. It has no existence apart from an object of some sort (although, of course, the object concerned need not be real, but may be illusory).
It is certainly true that the physical processes of sensation play a central role in our noetic relation to a domain beyond our apparent physical body. But it does not follow that what we perceive when we sense this ‘external world’ are sensations or even images of the world.
· The only coherent theory is that what we perceive is the world itself.
· The images we form in our minds of such primary perceptions are only ex post facto memories of what we perceived.
· The abstract concepts we form thereafter are not mere manipulations of concrete memories, but relations we intend to the objects initially perceived.
The fact that we perceive external objects, and not impressions or ideas of those objects, is certainly marvelous, so much so that we still cannot understand how that might happen. But our difficulty and failure to explain this marvel of nature is not a reason enough to deny its occurrence. That we perceive the world is obvious enough; how such a thing is possible is a distinct question, which we may never answer. Science does not normally deny the very existence of what it cannot thus far explain.
Note well, we can claim knowledge that we directly perceive the external world itself, without claiming to know yet just how we manage to do so. We know we can, because this is the only consistent theory we can posit, as already explained. But exactly what role the senses and brain play (other than memory production, storage and reactivation) in this evident direct perception is still an open question. The fact that a partial question remains does not invalidate the truth of the partial answer already obtained. There are many issues in the special sciences that remain unsolved to date – and we do not for that reason throw out the knowledge we already have.
It does not follow from such non-skeptical, objectivist theory of knowledge that perception or conception can never be erroneous. Errors in human knowledge are essentially conceptual, and it is the task of logic to minimize them. Perception sometimes seems wrong, after the fact, due to our noticing later percepts that seem to contradict the earlier. In such cases, we realize that in fact we drew some conceptual inference from the initial percepts, which the later percepts make clear was unjustified, and we correct our previous assumption. This is just an application of the laws of thought and the principle of induction to sorting out conflicting perceptions.
Once we comprehend human knowledge in this truly enlightened manner, it becomes clear why Hume was so confused and self-contradictory in his views of induction, and other logical and philosophical issues. If one starts with false premises, one is very likely to end up with false conclusions. He should have been more careful.
Philosophers like Hume have always found the idea that we might indeed be perceiving and conceiving the world out there, and not merely our impressions and ideas of it, difficult to comprehend or explain. This is understandable, because this seeming ability of ours (viz. external consciousness) is something truly surprising and, well, miraculous – no better word for it comes to mind.
But then these same philosophers take for granted that our inner perceptions and conceptions are valid and not in need of explanation. They apparently do not realize that this ability (viz. internal consciousness) is also miraculous – indeed, just as miraculous. For the difference between the two, after all, is just one of distance. And who is to say how big the soul (the subject of consciousness) is or where it is in fact located? Why do they assume that it is more ‘inside’ than ‘outside’ the apparent body?
In both cases, there is something marvelous, inexplicable – namely consciousness, a line of relation between an object and a subject. How can one existent (a soul, a spiritual entity) experience another (a mental or material phenomenon)? In the case of self-intuition, the subject and object are exceptionally one and the same. But even this is a marvelous event, that something can experience itself.
The mere fact of consciousness is the biggest mystery. In comparison to it, the issues of how far consciousness can go, and how in some instances it is aroused and made possible by sensation and yet the body does not block or distort our view – these are relatively minor issues.
Of course, a theory of the exact role of the senses remains highly desirable. Obviously, each sense organ (whether in humans or other animals) somehow gives the overall organism ‘access to’ a range of data of a specific sort, and no other: e.g. human eyes open the window to a range of light waves (the visible spectrum) but not to all frequencies (not to radio waves, ultraviolet rays or microwaves, for instances) and not to other modalities (such as sound or chemical signals). The different sense organs have evolved over millions of years (at different rates and in different directions in different organisms).
Without these sense organs, we would not (so it seems) be able to sense external reality. So their role is not only that of memory production, but they are somehow essential to the actual contact between the organism as Subject and material objects it perceives. Even so, to repeat, it cannot consistently be affirmed that what the Subject perceives are internal products of sensation. Nor is the explanation that sense organs serve to filter out some of external reality sufficient. The sense organs must have a more significant role in the Subject-Object interface. But what?
 I am stereotyping things a bit, because in truth Locke was somewhat aware of the problem, and so was Berkeley after him (and before Hume). Perhaps the philosopher most to blame should be Descartes. But I cannot here get into the fine details of history.
 This has come much later in the history of philosophy. Even Immanuel Kant, Hume’s intellectual successor, never grasped phenomenology, but instead produced a complicated system of philosophy that increased the appearance-reality chasm. Note that when I use this term, I do not necessarily mean the Hegelian or Husserlian attempts at phenomenology, though these two later philosophers certainly played important roles.
 The reader is referred to my work on phenomenology for more on this topic.
 Hume obviously in fact believed in the existence of the external world, since he invested so much of his time writing and publishing books for others to read!
 Whereas Locke used the word idea very generally (including all mental phenomena, even emotions), Hume distinguishes primary impressions from derivative ideas, i.e. simple empirical sensations from the more complex mental constructs made with them. However, I here use the term idea much like Locke, because Hume’s finer distinction does not affect the issue at hand.
 The word “intention” is very well chosen here, note well. It is not the idea, or the name for it, that intends the object – it is us, we the subject, who do. The word does not refer primarily to an act of consciousness, in the sense that Husserl defined consciousness with reference to some mysterious “intentionality”. Consciousness is not essentially an action, but rather a receptive event. No, intending refers to an act of volition. The subject (I, you) programs such an intention into every notion or symbol he produces. The subject wills his attention (awareness, consciousness) in the direction of the object concerned when he again comes across that idea or word. When we communicate, we pass such guides to mental action to each other.
 A verbal problem to always keep in mind is the equivocation of the word “sensations”: used in a general sense it refers to all sensory material, whereas more specifically it makes us think of touch sensations. Likewise, the word “images” tends to evoke visual images, but in the present context it is meant to refer to any resemblance, i.e. equally to auditory and other sensory phenomena. Such equivocations may seem anodyne, but they mislead many people.
 More precisely, memories are physical items (produced by sensations of visual and auditory phenomena) stored in the brain, which, when (voluntarily or involuntarily) reactivated, project mental images or sounds that we inwardly perceive and recognize as previously directly perceived (in the physical world, when that is the case). In the case of smells, tastes or tactile phenomena, I suspect we cannot in this way ‘recall’ past or present perceptions, but only ‘recognize’ them as familiar, so the term memory has a slightly different meaning. Note well that we do not commonly confuse our perceptions of material things and events with our memories of such perceptions; it is only armchair philosophers like Locke and Hume who equate these two experiences, quite unthinkingly.
 For example, just what is a “force” like gravity in physics? Or just what is “energy”? Isaac Newton admitted his ignorance, saying “hypotheses non fingo” (meaning, I have no explanation); and even after modern developments in physics, like the Relativity and Quantum theories, we still do not know just ‘what’ these abstractions refer to concretely or ‘why’ these processes occur. Despite this partial (and even crucial) ignorance, we do not consider physics less of a science. For what is science? It is not omniscience, but merely a guarantee that our current opinions are the best possible in the current context of experience – because the most rigorously induced.
 I leave open whether we can experience other souls. Some people suggest it is possible, i.e. claim a sort of other-intuition. Some people claim even to have experienced God.