Hume on Custom, Probability and the Reason of Animals

In section five, Skeptical Solutions to These Doubts, Hume describes the foundation of inference. “Custom ( habit), then, is the great guide of human life. It is that principle alone, which renders our experience useful to us…” (29) writes Hume. Reason and reflection are not enough to explain human understanding. I will reflect about a different example than used by Hume. Lets suppose I don’t know coffee is made with ground coffee beans and water. The question is: can I infer the mechanism of brewing if I see water and coffee brought inside a room, and coffee brought out? I would first have to know water can absorb molecules, I would also have to know that that ground coffee is penetrable, and water may travel through unlike rubber for example. It would also help if I knew what happened inside the kitchen, generally speaking. I can imagine water running through coffee and coming out clear. To answer the question I asked, no; I would not be able to infer that the pure water becomes coffee unless had certain experiences. I see why Hume explains custom is the great guide to human life.

In section six, Of Probability, Hume discusses probability and its influence on belief. Clear water will always boil at 100 degrees centigrade at sea level. As many times as I conduct this experiment, it ways be the case. I may not be educated in thermodynamics to be able to explain the phenomena, or even know water is composed of independent water molecules. But, I have a thermometer and the temperature never reaches above 100 degrees. Despite my ignorance of the phenomena, the fact that the water will boil at the same temperature every time will give me a strong confidence in understanding. Suppose a rascal contaminates my water supply with salt. The salt ions will dissolve and pull the water molecules towards them with a stronger force than the water molecules act on each other and thus raise the boiling point. My belief that the boiling temperature is 100 degrees now would be proportionate to the event.

In section nine, Hume extends cause and effect to all animals. I’m sure everyone is familiar with Pavlov’s Dog experiment where the he rings a bell preceding every meal and eventually the dog’s stomach begins releasing digestive juices after the sound of the bell. Furthermore, the intelligence of animals is rather well known today. Dogs can be trained to find bombs, drugs or help the disabled. This is not a surprise after all because animals need to utilize the principle of cause and effect for survival, something exploited in animal trainig. The mental faculties in animals are limited after all. Monkeys are caught by luring them with bananas in containers with opens small to retrieve a hand once it made a fist.

The Problem of Induction

In today’s post for the sexiest philosophy blog online, I’ll take a look at the fourth section of Hume’s Enquiry, and try to make sense of the so-called “problem of induction”. Hume begins by differentiating those things which are possibly true into either “Relations of Ideas” (true logically, by the parts making up the whole; something like a priori truths discoverable by mere thought) and “Matters of Fact” (true conditionally based upon objective reality). Then he explains that “Matters of Fact” are judged true or false through the use of cause and effect, which is where it gets really interesting (perhaps even sexy, some might say), because he says that the relationship of cause and effect cannot be understood outside of experience (it is not a priori given). But why exactly is that so important?

It’s important because most of what expect and “understand” in our daily lives are based upon the notion of induction, which is to say that we expect similar results from similar actions / situations. We have, every single day of our lives, experienced the law of gravity as true, and so we assume that when he drop a dense object from some height, it will fall downwards towards the surface of the earth. People don’t go skydiving and expect to fly up when they leave the plane. However, since induction is not given a priori, we cannot assume that our natural laws will hold at all times. A good way of understanding this which I have come across in my study of philosophy is a hypothetical example:

Imagine, if you will, an infinite (constructed, not absolute) room full of unlabeled boxes. You have been given the unenviable task of cataloging the contents of all the boxes. You open one box, and in it, you find 30 bags of Munchies Cheese Fix, the greatest snack known to mankind. You open a second box, and you find the same thing. And so forth, up to a million boxes, always finding the 30 bags of the delicious snack. You then leave the room and tell your employer that every box in the infinite room contains 30 bags of Munchies. Would you be justified in saying so? Of course not. The millionth-and-one box may have contained 25 bags of Munchies. Or perhaps it was full of venomous snakes. The point is, you can’t assume, no matter how many times the relationship has held true in the past, that it will hold true in the future. This is the problem of induction.

What Hume is pointing out is that, since everything we know about “Matters of Fact” (which is most of our knowledge) is based on cause-and-effect, which suffers from the problem of induction, then we cannot say for certain that many things we take for granted (all of physics, for example) will continue to hold true in the future. We might be able to say that it is probable, or likely, but we can never say it is definite or certain.

Sexy, sexy stuff.

Idea Empiricism in Hume

In the second section of the Enquiry, Hume writes about Idea Empiricism, claiming that "ideas... are copies of our impressions" (11). In particular, I like the phrasing of his example in the second proof that "a blind man can form no notion of colours; a deaf man of sounds" (12). With the exception of the missing shade of blue example that he gives, I think that this is probably how our minds must necessarily work. We are, as John Locke famously said, born a blank slate and we develop ideas based on experience and interactions with the external world. Children do not understand concepts such as “right” and “wrong” without being taught them, and the only thing that really seems to be inherent is our ability to reason and learn and understand ideas. But, as far as the ideas themselves are concerned, it seems reasonable to say that we develop them after experience and not the other way around.

One example of this comes from my own personal life, and one that I have spent a lot of time pondering. I am three different kinds of colorblind, and these three interact in odd ways depending on the lighting in a room, the material that things are made of, how much sleep I’ve gotten, etc. etc. This has the particularly annoying (interesting, some might say) effect that the same object will look like two completely different colors from day to day or even minute to minute. When I first explained this phenomenon to a close friend, he asked me the question, “then what do you think of when you think of the color red?” I had no response for him, and upon further reflection, I came to realize that I have no conception of the color “red” in any abstract sense. I am aware that such a color exists, and I have associated it with different objects from time to time in my life, but the idea of “red” is not one that I can conjure in my mind on its own. Due to the variable / non-fixed nature of colors in my experiences, I have never been able to know for sure what object is what color without asking someone else (someone who is not colorblind). If the same shirt looks purple one day, then burgundy the next, then blue, and so forth, I can never know for sure what color the shirt is, and more importantly for the context of Hume’s empiricism, I also do not know exactly what “purple”, “burgundy”, and “blue” mean. If ideas were inherent, and not derivative of experience, we might expect that this would not be the case. And yet, here I sit, living proof that it is.

Locke on Simple and Complex Ideas

In Book II of Locke’s An Essay Concerning Human Understanding, Locke explains and distinguishes the concepts of simple and complex ideas from which all understanding can be derived. Simple ideas are the source of all knowledge, where everything we understand comes from, and these ideas are respectable to the five senses we possess as human beings: sight, sound, touch, taste, and smell. Because these ideas are only known through the senses we can say that they are only known through experience and Locke describes the two forms of experience as sensation, which is when our senses actually experience the world through our bodily senses, and reflection, which is when our minds look inward to the reaction on our minds. Then there are complex ideas which are the combination or unification of several simple ideas to form one idea based on the various concepts we get from simple ideas, or the various senses through which we understand the simple ideas. Complex ideas can also be formed when we compare and or abstract “general ideas” from the various simple ideas that we have.

The concept of simple ideas being the basis for all that we know and the fact that simple ideas are known through experience can make it seem as though Locke is a materialist, in the fact that he focuses only on the experience that the simple ideas place on us. Which is another crucial part of this concept of simple ideas and that is that the mind is passive because it is being acted upon by these simple ideas through which we experience the world. But that is mostly through the sensation aspect of experiencing simple ideas while the reflection aspect requires us to look inward at the reaction or effect that these simple ideas have on us thus allowing us to truly understand these simple ideas. One of the most crucial aspects of all this is to understand that at no time is there a simple idea ever created, all the simple ideas that we experience, whether through sensation or reflection, already exist in the world and what we are understand is the idea but we are not creating it, which is the main reason that this concept of simple idea is a passive one.

Then there is the concept of complex ideas, which are the combination, comparison, or abstraction of simple ideas in order to create a grander general idea that is composed of the various simple ideas involved the thought process. This concept of complex ideas is the active aspect of this theory in which the mind is now acting for itself as opposed to being acted upon by the experience of simple ideas. In the process of creating complex ideas, whether combination, comparison, or abstraction, the mind must consider all the aspects of the simple ideas and the experiences placed upon them and then form a general idea regarding all these aspects, which will inevitably become the complex idea.

Knowing God, Unknowing Reason

“Our knowledge of our own existence is intuitive.” (pg. 274, 3) For Locke, knowledge is what the mind is able to perceive through reasoning with a connection or lack of a connection between our ideas. This is because knowledge only has to do with relations between ideas which are in our minds not of the world itself. Most of our everyday experience is subject to some opinions or judgments. We base our judgments on the similarities between our own experiences and the experiences described by others. We use reason to obtain judgment and knowledge. When it comes to knowing God, faith is the acceptance of the revelation and has its own truth that reason can’t find. However, reason is always used to determine which revelations are really from God and which are the makings of man. Reason may also include the use of the syllogism. "But God has not been so sparing to men to make them barely two-legged creatures, and left it to Aristotle to make them rational." (pg. 315, 4) It is possible and very common for people to be reasonable without having had any instruction in the use of the syllogism.

Locke on Language

No one can deny the huge role language plays in our lives, but at the very same time, a lot of us take it’s basis for granted. We never even consider breaking it down, the different kinds of words, where they come from, why we use them, what they really mean. It’s a whole system we learn as children, take for face value and move on. And ye, language, not just the ability to make noise, is what separates us from animals, it is the most important element we possess as a race. In chapters I though IV of book III, Locke breaks down language to its most simple of forms and builds upon this foundation. Ultimately as he states in chapter II, words mean nothing but the ideas to which we assign them, they are the tools that man use in order to get the invisible ideas floating around out of his head and into the world. It is not the words that have meaning; they mean nothing without the ideas. But his major focus lays in general ideas, because this isn’t as simple as particulars, assigning a certain word to a certain thing, this is giving a whole array of similar things a common identity.

And then there is the particularly interesting part in which he analyzes the difference between real and nominal essences of beings. The idea of “essence” has been a reoccurring theme in the works of Descartes, Spinoza, and now Locke. It was important when trying to prove the existence of God, but Locke brings it down to the world around us. According to him there is both real and nominal essences, Real, being the intrinsic value, and nominal pertaining to its observable properties. And yet, despite what we would assume differentiation to be based off of (the real essence), it is based off nominal essence. He goes on to state “species that are distinguished by their real ideas [are] useless” (Locke, 186). This may seem backwards, but after reading through point seventeen we come to realize that the basis of words is solely what we perceive, this is what he had laid out in his previous chapters. Words, general terms, they rely on the characteristics things posses, and then also privation. Cold is the absence of heat; man is what the particular “Joe” lacks. This is a turn from Descartes who could and would not rely on his senses as a connection to reality.

Locked on Common Sense

In the opening of the Epistle to the Reader, Locke describes how a conversation shared amongst him and his friends sparked an intense and laborious debate and subsequent impasse, on certain philosophical principles. Locke, noticing that the conversation was limited by boundaries of human knowledge, decided to lay out a philosophical framework of understanding that functioned within those boundaries. The complex nature of the metaphysical quest for universal knowledge does not lead to a suitable and functional understanding of knowledge. The design of his framework beginning in Book I immediately reduces some of the heavily debated points covered by other philosophers, to that of speculation. Locke’s method focuses on where conscious ideas come from, what ideas are and their certainty and extent, and the nature and grounds of faith and opinion. Physical considerations of the mind, how essence body and spirit come to have sensation in our organs, ideas in our understanding, and the dependence of ideas on matter, are NOT matters of primary focus in Locke’s platform. What IS of focus, directly counters views that metaphysical philosophers such as Descartes had pertaining to the trusting (or lack thereof) of corporeal senses. Locke places a heavy emphasis of the use of senses as that which establishes knowledge through sensation experience and reflection.

How much we know the extent of our comprehension can be very useful, even considering the limitations of our knowledge capacity. I like the sailor example that Locke uses when tackling the limitations of knowledge- a sailor may never know or fathom the deepness of the ocean, but is capable of using a line of known length to assist in the traversal of unknown waters to his benefit. By experiencing through the senses, our mind processes and operates. We think and reflect to produce ideas, which in turn lead to greater knowledge. Without these experiences to sense and reflect on, we remain in an infant or ‘tabula rasa’ like philosophical state of knowledge. The senses produce repeatable simple ideas which can complex to form an infinite variety of complex ideas. Because the mind can neither make nor destroy these simple ideas, if we do not have the ability to sense something, we do not have the ability to create ideas and in turn extensive knowledge on it. In reflecting on all of this, I tried to come up with some type of sense that I do not recall ever experiencing- namely that the experience of telepathy. Locke would probably conjecture that we are not able to have knowledge of the transferring of thought, if we have never experienced a simple telepathic process sensation to produce the simple ideas. With the pretty sexy stuff running around in the 7 billion minds that inhabit our planet, maybe that’s not so much of a bad thing.