What Is Free Will? (Thinking About Thought - Part 3)

Hume has so far developed a fairly convincing argument for how the human mind forms ideas about anything.  You can read his theory in Part 1, Part 2, and the Summary.  Now Hume devotes the rest of his book, An Enquiry Concerning Human Understanding, to applying his theory to various philosophical problems.  If you are wondering why I am bothering to go through this book, it is because, first of all, I find Hume to be fascinating and convincing; secondly, his arguments shaped how later influential philosophers and theologians thought; thirdly, he is often quoted today by the new 'militant' atheists (like Richard Dawkins), and finally, this book provides his argument against miracles, which is often quoted but can only be understood and critiqued in light of the whole book.  With that said, today we will look at the problem of free will.  Argues Hume, free will (liberty) is not opposed to necessity - in a common sense outlook on life, both work together to give us true freedom.

Chapter VII – Of the Idea of Necessary Connection

Part I

When a match is struck, why does it produce both light and heat?  When a billiard ball hits a ball at rest, why is the force of the one transferred to the other?  Hume has argued that, to the mind, any effect is conceivable from a single cause; only experience can determine what the actual effect is.  But since the same effect is always produced from a single cause (heat always comes from a lit match), then there must be some force or power or energy that connects the effect to the cause, that limits the effect so that it is what it is and not something else.  This power is termed a necessary connection, and was the topic of much philosophical speculation.  In this chapter Hume examines whether the nature of a necessary connection can ever be known.

The words ‘power’ or ‘energy’ or ‘necessary connection’ are ambiguous and difficult to define.  But since they communicate a single idea, the best way to shed some light on this ambiguity is to produce the impression from which they are derived.

There are two sources of impressions: outward senses (sight, touch, smell, etc) and internal senses (like love, hate, etc).  If we cannot find an impression of necessary connection in the first, perhaps we can in the second.

External objects, Hume argues, which are offered to our outward senses, never reveal their powers of necessary connection to us.  If they did, we would be able to reason out the effect of a cause without needing any recourse to experience, which Hume has already shown to be impossible.  ‘It is impossible, therefore, that the idea of power can be derived from the contemplation of bodies, in single instances of their operation…’

Perhaps we are aware of necessary connections through internal impressions?  We desire to walk; an act of volition produces the motion of our leg and results in walking.  There was a cause (volition) and an effect (motion of leg).  The power connecting them we call consciousness.  This, then, it would seem, is the impression from which we get the idea of necessary connection.

On further reflection, however, it becomes apparent that consciousness is merely a substitute for the phrase ‘necessary connection’, and is not the impression itself.  We know that volition can cause leg movement through experience, but as to how the connection between mind and body works, we are completely ignorant.  Hume offers three arguments to show that this is the case:

1. The soul/body dichotomy is the greatest mystery: how pure spirit could influence gross matter.  If by our minds we could move a mountain, this would be no less mysterious than if by our minds we could move a limb.  None of these would be mysteries if we actually knew the power we call consciousness; the fact of the mystery reveals that we do not.

2. We cannot move our liver in the same way we can move our legs.  Why not?  Why is volition limited in its effects on the human body?  If we could find a power present between the mind and legs that is not present between the mind and liver, such a question would not perplex us.  But the cause (volition) is the same for both, with no sensible reason for the different effects.  We only know that the effects are different through experience, and not through an understanding of consciousness.

3.  Anatomy teaches us that, when we will the leg to move, we are actually willing motion in nerves and muscles, not in the leg itself.  ‘Can there be a more certain proof that the power, by which this whole operation is performed, so far from being directly and fully known by an inward sentiment or consciousness, is, to the last degree, mysterious and unintelligible?  Here the mind wills a certain event: immediately another event, unknown to ourselves, and totally different from the one intended, is produced: this event produces another, equally unknown: till at last, through a long succession, the desired event is produced.’  If we claim to know the power we call consciousness, then how could volition to move the limb and the movement of the limb be connected, not by a power that moves the limb, but a power that moves things of which we have no understanding?

Perhaps the impression that produces the idea of necessary connection is found in the mind, not when it wills the body to move, but when it brings forth ideas out of nothingness, reflects on them, and discards them in favour of new ideas.  But alas this, too, cannot be the source of necessary connection:

1. To know necessary connection implies that we know the cause, the effect, and why the relation between them is as it is.  But what is more mysterious than the relation between the soul and the ideas that are produced?  We certainly have no knowledge of necessary connection from here.

2. The authority that our mind has over ideas is limited by experience (ideas must be copies of impressions), and the authority that our mind has over our passions is weaker still.  Does anyone pretend to know why this is?  If we claim to know this power, then we must.

3. This necessary connection between mind and idea, whatever it is, seems to vary, such that the power of the mind over its thoughts is different when one is hungry than when one is full, or in the morning than late at night.  There is no way to account for this variation; it lies well outside our ability to understand.

No, it seems that we can only know the conjunction between objects (such as fire conjoined with heat), but can never know anything about the connection between them.  This has led some philosophers (namely, Malebranche) to a fairly strong conclusion: the only connection that can exist between anything is God.

Malebranche’s argument goes as follows: ordinary gardeners quickly learn that sunshine and water and soil are needed for plants to grow.  This becomes so commonplace to them that they forget that they do not really understand why this is – what is the power that connects these disparate entities?  But when something extraordinary occurs that they do not readily understand they are quick to attribute it to a higher intelligence, because they cannot think of any natural power that could produce such an event.  But, says Malebranche, in reality there is no natural power that can be known to produce any event, even the growth of a plant!  There is no such thing, then, as a cause, there are only occasions.  These occasions are conjoined together by the will of God, who wished that they should be together for the regulation of the universe.  Heat comes from fire because God causes the heat to come from fire; heat always comes from fire because this is how God continually wills it.  Our minds produce ideas because God intervenes between our volition and the idea itself.  Our bodies walk because God agrees with our will to walk, and provides the necessary connection for each step that we take.

Says Hume, these philosophers ‘rob nature, and all created beings, of every power, in order to render their dependence on the Deity still more sensible and immediate.  They consider not that, by this theory, they diminish, instead of magnifying, the grandeur of those attributes, which they affect so much to celebrate.  It argues surely more power in the Deity to delegate a certain degree of power to inferior creatures, than to produce everything by its own immediate volition.  It argues more wisdom to contrive at first the fabric of the world with such perfect foresight that, of itself, and by its proper operation, it may serve all the purposes of providence, than if the great Creator were obliged every moment to adjust its parts, and animate by his breath all the wheels of that stupendous machine.’

Beyond this, Hume provides two arguments for refuting these philosophers:

1. Malebranche’s theory that God constantly produces the necessary connections goes so far beyond our present experience that ‘we are got into fairy land.’  Hume doesn’t say that it might not be true, but rather that it is completely impossible for us to know one way or the other.  He prefers to limit his inquiries to what can be known, and to avoid idle speculation, especially when that speculation gets treated as dogma.

2. Malebranche’s theory is just as unprovable as the theory that necessary connections have natural origins.   So to jump from a natural explanation, the truth of which cannot be known, to a supernatural explanation, the truth of which cannot be known, solves nothing.  ‘All we know is our profound ignorance in both cases.’

Part II

It would seem, then, that all we ever see are strings of cause and effect. Custom teaches us what effects are conjoined with what causes, but never reveals why those effects from those causes.  Since we have investigated both inward and outward impressions and have not pinned down that impression from which necessary connection is derived, it would seem that necessary connection is an empty and meaningless phrase.

But one other source has yet to be examined.

We know that an effect follows a cause because we experience it.  We would never declare that effect to be connected to that cause based on one observation alone; we need to experience it multiple times (custom).  Customary conjunction (the conjoining of a cause to an effect over multiple instances) leads to a new feeling or sentiment: namely that, if I see the cause, my mind expects or transitions to the effect.  This feeling of the mind is a customary connection, and is the impression from which necessary connection is derived.

On seeing a cause/effect relationship for the first time, we can say that the two events are conjoined.  Upon seeing the same effect from the same cause multiple times, we can say they are connected.  ‘What alteration has happened to give rise to this new idea of connection?  Nothing but that he now feels these events to be connected in his imagination…When we say, therefore, that one object is connected with another, we mean only that they have acquired a connection in our thought.’  Customary conjunction produces the feeling of belief, from which arises customary connection.

This is a surprising conclusion.  Hume is arguing that we can never know anything about the power that connects a cause with an effect.  We know that such a power must exist, but the only reason we know this is because of custom.  Thus, when we say ‘cause’, we can only mean ‘an object, followed by another, and where all the objects similar to the first are followed by objects similar to the second,’ and an effect can only be defined as ‘an object followed by another, and whose appearance always conveys the thought to that other.’  These definitions do not tell us anything about why causes and effects are linked together, nor are we capable of ever knowing.

Chapter VIII: Of Liberty and Necessity

Part I

Do humans have free will or not?  Hume builds on the arguments from the last chapter to show that this old philosophical argument (yes, Hume was finding it old back in the 1700s) is based more on different definitions of the words, than on any real disagreements.

Hume begins with necessity.  In the material world we infer a necessary connection between a cause and its effect after we have experienced it multiple times.  We never catch a glimpse of the necessary connection itself, but only have the customary connection between them in our minds.  This we refer to as necessity: a ball, when held up in the air, has no choice but to drop when it is let go; an object at rest has no choice but to remain at rest until something else intervenes.  (That is, presuming that the course of nature has not changed).

Using custom, we can form predictions: if I let go of this ball, it will fall.  I have no idea why it will fall (the force is called gravity, but the true nature of this power cannot be known), but I believe it will fall nonetheless, and indeed it does.  Sometimes our expectations are not realized, but this is not because custom has failed us; rather, some opposite cause may also be at play.  The ball may not fall because a powerful wind is blowing up from the ground, such that it stays suspended in the air.  Had I known about this cause, I may have been able to infer the outcome.  More complicated systems, like the weather, have so many different causes working simultaneously and in differing degrees that prediction is nearly impossible and quite inaccurate.  But even so, it is still bound by necessity; we just don’t know all of the factors at play.

Necessity, then, is only a customary connection that allows us to predict an effect based on the cause.  What is interesting is that the mind does not perceive objects any differently from how it perceives human nature.  Human actions are dictated by motives.  If we knew the cause (motive) of a human action, we could predict the effect (action).  Since human motives are universal, our minds are able to operate through custom to predict the actions of any particular human.

A prisoner, for example, is seeking to escape, but he sees the causes of his inability to escape: the iron door, the cement walls, the strength and integrity of the guards.  The prisoner’s mind treats all of these the same, and uses them to infer that escape is impossible.  The thickness of the walls allows the prisoner to infer that digging is in vain; the moral superiority of the guard allows the prisoner to infer that bribes will never work.  Both physical causes and causes of the will are brought together to form one inescapable conclusion.

Indeed, all of the social sciences are based on the idea of necessity in human behaviour.  If any single motive could produce just any behaviour, there would be no way to critique a poet, or study politics, or trust history.

‘Thus it appears, not only that the conjunction between motives and voluntary actions is as regular and uniform as that between the cause and effect in any part of nature; but also that this regular conjunction has been universally acknowledged among mankind.’

We infer effects from causes for both natural objects and human volition.  Namely, if I could understand the different motivations of a person, I could predict their behaviour.  My friend is coming over; I can infer, based on her character, that she will not rob me.  But perhaps an unexpected change has come over her and she does; if I knew this new motivation, I could have inferred this different outcome.  Such is necessity, and this definition is, perhaps unbeknownst to them, agreed on by everyone.

What then of liberty?  According to Hume, liberty is in no way at odds with necessity.  ‘By liberty, then, we can only mean a power of acting or not acting, according to the determinations of the will.’  Liberty is not freedom to do everything; it is the freedom to choose whether or not we will act.  That a certain motive, given a certain circumstance, will produce one effect and not another, that is necessity.  Whether I choose to follow through on that action, that is liberty.

Part II

Hume concludes this chapter by showing that these definitions of necessity and liberty are essential to morality.

Suppose that I murdered someone in cold blood.  According to the law, I must answer for these crimes.  But this law presupposes some sort of necessity: namely, that I had a motive, and acted on it.  If we worked by actions alone, and actions are temporary, then I am as innocent after the crime as I was before it; only during the crime was I being abhorrent.  Since it is wrong to persecute the innocent, it would be wrong to seek vengeance on me.  But, if actions are necessarily connected to motives, then there was a cause within me, some defect in my character, that caused the murder and persists after the action was complete.

Similarly, if I were to repent of my crime and show through my actions a changed life, I would still be responsible for the crime, but I would earn the pity and respect of others.  Why?  Because my repentant actions reveal a changed mind and thus changed motives. 

We prosecute based on motive.  Premeditated murder is worse than spur-of-the-moment murder.  When the same effect (murder) is judged differently, this presupposes necessity.

Liberty also is obviously essential.  If we were all bound to act the way we did, then we could not be guilty of any crime.  The law presupposes that we had a choice, and makes allowances for situations in which there were no choice (such as self-defence).

What if liberty is an illusion?  What if there was a first cause set up in such a way that all causes and effects that followed, both of the natural and volitional kind, were preordained?

Hume considers this from the perspective of God, and addresses two different conclusions:

1. If all human action is ultimately the result of a chain of necessity, with no room for liberty, and at the end of the chain is a good God, then humans can never be criminal, for their actions are reflecting the will of a good God.  Responds Hume to such a claim, the human mind is incapable of seeing vice as virtue, much as it cannot see deformity as beauty.  Yet to imply that a good God is ultimately responsible for actions that we would call criminal would force us to redefine ‘good’ in a manner alien to the workings of the mind.

2. If crime is real, and God is the ultimate cause, then we must retract the attribute ‘good’ or ‘perfect’ from God.  Here Hume says that the philosophical difficulties to respond to such a claim are so great that he could never answer it.  If God preordains everything, there seems to be no way of reconciling human sin to God’s perfection, and God becomes guilty of creating sin.  Rather than speculate on such matters, Hume remembers that the sceptical philosophy avoids such impossible scenarios, and returns, ‘with suitable modesty, to her true and proper province, the examination of common life; where she will find difficulties enough to employ her inquiries, without bounding into so endless an ocean of doubt, uncertainty, and contradiction!’

Final Questions/Thoughts
If you were not blown away by what Hume records in these chapters, it is either because I did a poor job summarizing, or you haven't had time to process.  Because what Hume is saying about necessary connection is mind-boggling.  Essentially he says that we can never, no matter how hard we try or how great our science developes, understand why things work the way they do.  Why this effect, and not another?  Sure, we can scientifically determine that force is transferred from one billiard ball to the next, and we can even develop models to determine how the molecules of the one ball interact with the other to transfer that force.  But ultimately we come to a place at which our understanding comes to a halt.  Namely, why do matter and energy behave the way that they do?  This puts a serious halt to any form of sciencism, which claims that science is both necessary and sufficient for understanding the world.

I wonder about his liberty/necessity argument, and if he would have modified his argument based on current addiction research.  How free is free?  Our liberty is restrained by the necessity of cause and effect (I can't choose to live while drinking poison, for instance), but I wonder to what extent our ability to choose is dictated by our genes?  How much liberty to choose does an addict really have?  And is this reduction in liberty one of the great evils of a consumer-driven society?