Plato’s Republic Introduction – Lecture 1

October 10, 2012

Even though we can find all of this information on the internet, we might as well remind ourselves of some of the facts of Plato’s life. Of course none of this helps us understand his philosophy, but it does help us situate his thought, which will be useful when we come to look at its social and historical context. Plato was born in Athens in 427 BC into a very wealthy and aristocratic family. Apart from his intellectual life little is known about him. He was probably a student of Socrates, since he wrote so many dialogues about him, and after his death he set up his own philosophical school, the Academy, which is the precursor for the university system. One of the few incidents of his life that we do know about is his rather unfortunate adventure in Syracuse where he attempted to advise unsuccessfully both the tyrant Dionysios and later his son in political affairs. Returning to Athens, he died in 347 BC of natural causes.

Far more important, however, than these small details, for understanding the Republic, is the social and political context. The most important of these is the politics of Athens itself which was a radical democracy at the time. All important decisions of the city where made first of all by the Presidents (prutaneis) and then the Council of Five Hundred (boulē), both of whose members were chosen by lot. They then called the Assembly (ekklesia), which citizens were paid to attend, and who voted on the legislation. All males citizens of Athens were allowed (indeed were expected) to attend. Foreigners, slaves and women were excluded. Out of a population estimated to be 300,000 – 350,000, around 50,000 voted. It was this democracy that put Socrates to death for corrupting the youth in 399 BC, during the political upheaval following the rule of the Thirty Tyrants, of which Plato’s own relatives, Critias and Charmides, were associated. It should not surprise us, therefore, that in the Republic, Plato is not going to complimentary about democracy.

Although Plato did not date his dialogues, which is the form his published work takes, perhaps mimicking the style of his teacher Socrates, we can date the different dialogues through their style and content. Following this procedure, we can say that the Republic is a middle period dialogue. The first dialogues, such as the Apology (about Socrates’ trial) and the Crito, mostly followed the teaching of Socrates (and indeed it is from them that we have knowledge of Socrates’ philosophy since he did not write anything himself) and were concerned mainly with ethical and moral questions. Moreover, they tended to end inconclusively. Through questioning his interlocutors, Socrates would show that they did not understand their own answers to questions such as ‘what is justice?’, but he would not follow their puzzlement by giving his own answer. Thus the reader, perhaps purposely, was left equally baffled. The middle dialogues, where Socrates was still the main character, though they still concerned ethical questions, where no longer dialogical in form, though the Book 1 is still similar to the early dialogues. They also began to present more of Plato’s own philosophy, especially what has come to be known as the Theory of Forms (though there is little evidence that Plato actually called it that and there still much debate amongst commentators about what this so called theory might be).

The major theme of the Republic is Justice. The Greek word that Plato uses for justice is δικαιοσύνη (dikaiosyne) which can also mean ‘righteousness’. The aim of the Republic is simple. It is to convince you that justice is better than injustice. For Plato, there is an analogy between the just person and the just city. Each is a whole that is made of parts. If we first think of the city, then it is made up of three classes: the artisans, the warriors, and the guardians. The just city is one that is well ordered. It is ordered because it is unified and stable. What creates instability and disunity is movement and dissent. Everyone has their place and function, and everyone should stick to their place and function. It is possible through education you might change your status, but on the whole one is born either artisan or a warrior or a guardian; one cannot become so. Just as the city is divided so is the human soul and most importantly between reason and desire. A human soul, whose parts are governed by reason, will be like the just city. It will stable and unified. A human soul that is governed by desires will be running from one pleasure to the next and will have no integrity. The analogy between the city and the soul works because the guardians are those people whose souls are governed by reason rather than by desire. It is they who should therefore rule the city, because it is they will be guided by the idea of justice, rather than the artisans or the warriors.

Plato’s ethics, though it does not require it, is guided by his metaphysics, since the theory of Forms explains the possibility of the idea of justice which directs the souls of the guardians. What corresponds to the unity of reason, and the unity of the city, is the unity of the idea. There are many just things in the world, for example, but there is only one idea of Justice. There are many good things in the world, but there is only one idea of the Good. The guardians should be allowed to rule the city because only they are capable of thinking the Forms. Although, as White explains, Plato spends much time showing why they should rule the city and what might be their motivation to do so, he does not explain why everyone else, the artisans especially, should be happy that their democratic power should be taken away from them for the sake of a well-ordered city and why anyone, if they were not part of the guardians, would be perfectly happy to remain enclosed within their own strict place in life (White, 1979, p. 28).


White, N. (1979). A Companion to Plato’s Republic. Indianapolis: Hackett.

Joy and Sadness in Spinoza – Lecture 2

October 7, 2012

When we come to Spinoza’s analysis of affects the fundamental distinction is between active and passive ones. This is because the essence of singular things is to be understood in terms of power. Since only existence is what distinguishes one thing from the other, each thing seeks to preserve its own existence (‘Each thing, as far as it can by its own power, strives to preserve in its being’ IIIP6), otherwise it would cease to be what it is. Any singular thing, however, is also linked to an exterior environment, and the more complex it is, the more complex these relations will be. What defines the nature of human beings, is not some ‘natural perfection’, or that they are created in the image of God, (all ideas guilty of the worse kind of anthropomorphism for Spinoza), but the complexity of their bodies and therefore the complexity their relations to other external bodies. These relations can have two basic forms either active or passive: either I determine myself in relation to these external bodies, or they determine me, and the more that I determine myself the more my power increases, and less I determine myself, or the more that I am determined by external causes, the more my power decreases.[1]

The distinction between passive and active affects is understood by Spinoza through two fundamental affects: joy and sadness. We might say that for Spinoza human affective life is made up of three basic affects: desire (conatus – the striving for self-preservation that all singular things have), and then joy and sadness. All the other emotions that Spinoza describes in the Ethics are merely variations of these three basic affects but the most fundamental are joy and sadness.[2] How can we understand this difference between joy and sadness? Spinoza explains it in proposition 11 of Part 3:

The idea of any thing that increases or diminishes, aids or restrains, our body’s power of acting, increases or diminishes, aids or restrains, our mind’s power of thinking.

Whatever increases or diminishes the power of the body to act also increases or diminishes the power of the mind to think. This follows, Spinoza writes in the demonstration, from 11P7 and IIP14. The first is the statement of parallelism – the order and connection of things is identical to the order and connection of ideas – and the second is that the mind contains what the body experiences, and the more complex a body is the more sophisticated these experiences are. In the scholium, Spinoza explains that our minds, because of the complexity of our bodies can go through many changes. These changes, to use Bennett’s expression, are to be thought in terms of ‘up and a down’, as the passage from a great or lesser perfection (Bennett 1984, p.257). What does Spinoza mean by ‘perfection’ in this context? Again we have to remind ourselves that for Spinoza human beings are not a ‘dominion within a dominion’. We are part of the universe of infinite series of causes and effects, about which we cannot have absolute knowledge. The human body is essentially vulnerable to external bodies, because it has so many complex and involved relations to them. To increase my power to act is to increase my power to determine myself and act against these external bodies through the desire of self-preservation, and my power to act is decreased when these external bodies threaten by existence. I can only be destroyed, Spinoza writes, by external causes. Perfection is an affirmation of existence. The more perfect something is the more reality that thing has, and therefore the more power to act it has and thus the more power to think.

It is with respect to this increase and decrease of the power to act that we can understand the two fundamental affects joy and sadness. Joy is the affect by which the mind passes to a greater perfection, and sadness to a lesser one. There are things in the world that make us joyful and there are things in the world that make us sad. This is all that we need to understand passive affects. First of all these affects have to do with the body, but we know from part 2 that the mind is the idea of the body and that the power of the mind to imagine things depends on the existence and relation of the body. Thus joy and sadness, at least for human beings, does not just involves direct relations with our bodies, but also with our imagination, the idea of the bodies we have, and the ideas of how they are changed or modified by external bodies (whether persons or objects). For the most part, because of the very way we do have ideas of our body, these ideas are inadequate (because we do not have an adequate understanding of the relation our body to the other bodies).

As long as the body is affected by an external body, Spinoza writes in the following proposition, the mind will regard that body as present, and as long as the mind imagines that external body as present, then our own bodies will be affected in the same way. This means that if the mind imagines an external body that increases the power of the body to act then the mind’s power of thinking will be increased, and it will feel joy, and if it imagines an external body that decreases the power of the body to act then the mind’s power of thinking will be decreased, and it will feel sadness. Then mind, then, Spinoza states in the corollary of IIIP13, will try to stop imagining those things that restrain the power of that body and its own, and in the scholium this explains the difference between love and hate. One who loves strives to make present the thing he loves, because this is a passage to a greater perfection through the idea of an external cause, joy, and one hates, for the opposite reason, will try to destroy the thing that she hates.

Through imagination we have, therefore, very complex relations to external bodies. It means in IIIP15 that anything can be the accidental cause of joy or sadness, and we can love or hate those things without any cause known to us because they are similar in our imagination to other objects that affect us. Thus, as in IIIP16, by the mere fact that there is a resemblance to one object or another, we can be affected by joy or sadness. Moreover imagination also opens us up to time. We are affected by the same joy or sadness, Spinoza argues, whether we are talking about a past or future external body, or whether we are speaking about a present one. Thus the imagination retains past impressions of encounters which still affect it in the present, and as the same time can project these impressions, both present and past ones into the future. As long as I am affected, Spinoza writes in the demonstration, I will regard the external body as present, even if it doesn’t exist. The image of an external body is the same whether it exists in the past, present, or future; it is there in my mind, and it affects me. We might say that accidental causes of affects are always the mediation of one affect by another affect, either through different affects, or different times. In each case, for Spinoza, the causes of these affects are inadequately understood and thus experiences passively, whether they are sad or joyful.

It is the intersection between affects and affections which determine the specific nature of human emotions. The mind strives to imagine and recollect images that augment the power of the body to act, and to keep before those ideas which exclude the existence of things that diminish my power to act. It is these images that carry associative feelings from the past, which reflect the causal interactions between my body and others that have left their traces within me, such that different bodies with different traces will react differently in the present then I will. My body is all my past interactions which affect my mind carried through into the present and projected into the future.

Our relation to affects is not merely individual but social (and this will be very important in part 4, to show that the self-interest does not contradict friendship and sociability). It is true for Spinoza that each being strives to exists, but the form that this striving takes is determined by the nature of that being. Human beings are social beings. This means that my own well-being is inconceivable without others. I am not first an isolated being which then encounters others; rather, my very individuality is inconceivable without my relations to others that care for me, and I care for them. It is not that the individual pursues his or her own interests against the interests of others but that to be an individual is to be already acted upon and act with others. My existence, as a determinate mode of infinite substance, is already involved with the existence of others. This is why from IIIP21 Spinoza argues that if we imagine the thing that we love affected with joy and sadness, then we too will be affected by joy and sadness and we will love those who affect those we love with joy, and hate those who cause them sadness. We too also feel empathy towards other beings like ourselves (IIIP27). If the nature of an external body is like our body, then if we imagine that body involving an affect, then we too will be affected by that same affect, which explains the feeling of pity that we have for those that suffer. For human being, affects are imitative. We do not only affirm ourselves but also those we love. Those we love are those whose existence gives us joy, and we wish to give them joy, and exclude from existence everything that gives them or us sadness. This is not altruism as an idea but the power of imagination. If we imagine someone like us to be affected by an affect, we can likewise imagine ourselves also so affected and so also be affected. This similarity is not one of common identity but a direct apprehension through bodily awareness. Thus in every bodily experience there is a direct relation to other bodies and this must always be the case for human beings. And this is both the cause of conflict and harmony. Every human emotion, whether positive or negative, is caused by bodily imaginings, and our ideas of good and evil arise out the joy and sorrow of being in our bodies. What is good is not what we judge but what we desire. We judge it good only because we desire it, and not the other way around.[3]

There is no Good and Evil in the moral sense. Rather they are relations between bodies. What is good is what augments my existence; what is bad is what diminishes it. If we think of this in terms of food, Deleuze explains, then what is bad for us is what destroys our bodies (Deleuze 1983, p.34). This is what we mean by poison. What is good is what suits our nature, and what is bad is what doesn’t. If something suits our nature then it increases our power, if it doesn’t, then it decreases it. Thus, as Deleuze writes, the aim of the Ethics is replace transcendent morality with an immanent ethics, which is nothing else than the relation between bodies (Deleuze 1983, p.35). It follows from this that Spinoza does not see any benefit to sadness at all. Sadness does not teach us anything. It only makes us weak, and from this weakness arise feeling of ‘hate, aversion, mockery, fear, despair…, pity, indignation, envy, humility, repentance, abjection, shame, regret, anger, vengeance, cruelty…’(Deleuze 1983, p.39).

Every individual, for Spinoza is a singular essence, which is a degree of power. This degree of power is determined by an ability to be affected. Thus an animal is not defined, Deleuze explains, in Spinoza as a species, but in terms of its power to be affected, by amount of affections that it is capable of (Deleuze 1983, pp.39–43). When it comes to human beings this power of being affected is defined by two types of affections: actions and passions. Actions explain the nature of the individual (what it can do) and passions how it is affected by external bodies. The power to be affected is present as the power to act, when it is ‘filled’ by active affections of the individual, and the power to suffer when it ‘filled’ by passions. For every individual the power to be affected is constant, but the relation between active and passive affections is variable. It is not only important, however, to distinguish between actions and passions, Deleuze adds, but between two kinds of passions. If we encounter an external body which does not suit us, then the power of this body is opposed to the power of ours and as such it acts as a ‘subtraction’ or ‘fixation’. It takes diminishes or subtracts from our power to act, and the passions that correspond to this relation are sad. In the opposite case, if we encounter an external body that suits us, then its power is added to ours, and we are affected by the passion of joy. Now joy, just like sadness must be separated from our power to act, since it is a passion and must therefore have an external cause, but the power to act increases proportionally such that we reach a point where passive joy ‘transmutes’ into active joy. There cannot be, however, any active sadness, because sadness by definition decreases the power to act and thereby, the power to exist, and not being does not seek to preserve its existence. Suicide, for Spinoza, is not a sign of strength but weakness: a more powerful cause outside of me causes me to take my own life, if even I think mistakenly that I am the cause.

All the sad emotions and passions of our lives represent the lowest point of our power, and thus of our existence. Sadness alienates us from ourselves. We are totally at the mercy of feelings that come from the outside, and totality powerless from stopping them. Only joy can help us to act. If we allow ourselves to be affected by those things that bring us joy, then we become more powerful and more active. One issue for Ethics, then, is how can we experience the most joy so that this feeling of joy can be transformed into ‘active free sentiments’ especially since our nature since to make us so vulnerable to sadness and unhappiness (are we not the most miserable creatures on this planet?), since we are constantly affected by external bodies that we do not understand. How then can we affirm ourselves when we are buffeted from negative passions from all sides? This is the question that part 4 will seek to answer.

Works Cited

Bennett, J., 1984. A Study of Spinoza’s Ethics, [Indianapolis, IN]: Hackett Pub. Co.

Deleuze, G., 1983. Spinoza : philosophie pratique, Paris: Éd. de Minuit.

Lloyd, G., 1996. Routledge Philosophy Guidebook to Spinoza and the Ethics, London; New York: Routledge.

Rorty, A.O., 1987. The Two Faces of Spinoza. The Review of Metaphysics, 41(2), pp.299–316.

[1] This is always relative for Spinoza, since as finite determinate modes, human beings can never totally be separated from external causes. The aim of the Ethics cannot be to rid ourselves of affects, since they belong to our nature, but to understand them better. Whether we do so is itself is not up to us. Self-determination is not free will for Spinoza but the recognition of necessity (Rorty 1987).

[2] Bennett lays these out, though he is not convinced that Spinoza should treat desire in the same way that he does joy and sadness (Bennett 1984, pp.263–4).

[3] Geneviève Lloyd gives an excellent explanation of this (Lloyd 1996, pp.77–6).

Kant and his Contemporaries – Lecture 2

October 5, 2012

We have already argued that one way of thinking about Kant’s thought is as the mediation of the two competing camps of modern philosophy, rationalism and empiricism. Such mediation, however, will entirely formal and empty, if we don’t understand the particular nature of Kant’s response to both camps; that is to say what he takes and rejects from rationalism, and what he takes and rejects from empiricism. Such a selection itself would not be possible if Kant were not able to conceive of a completely different way of thinking about subjectivity that he calls transcendental idealism. So it is not just a matter of joining two opposite philosophical schools together, which would be impossible and nonsensical, but of looking of the problem they intended to answer, in an entirely different way.

What was that problem? How do we join together or bridge the subjective with the objective world. In other words how do we know that what think, see, and feels is exactly the same as what is out there. How do we know that our representations are true at all? We shall take, for reasons of brevity, Descartes and Hume as our representatives for rationalism and empiricism respectively and we shall first of all begin with Descartes.

The most important thing to emphasis in reading Descartes, as Hatfield quite rightly emphasises in his introduction to the Meditations, is that we cannot make sense of his philosophical work without acknowledging their scientific origin.(Hatfield 2003, pp.1–36) Descartes’ problem, then, was how to justify philosophically the new science of the 17th century and to do so he had to reject the traditional Aristotelian metaphysics he was taught and which was the general way in which his contemporaries thought about nature. For this reason, we too must remind ourselves, if very schematically, what this metaphysics is.

At the heart of Aristotelian metaphysics is substance. Perhaps when we ordinarily think about this word we think of matter. When I ask you ‘what is the substance of this table?’, then you might answer ‘atoms’ or some such other word. But this is not how Aristotle thought about substance (in fact he had an entirely different word for matter, which was hyle). Aristotle’s word for substance is ousisa, which means ‘being’ or ‘a being’. In other words ‘substance’ names everything that is. The question then when I ask you ‘what is the substance of this table?’, is what makes this thing a table as opposed to chair, or horse and so on. It can’t be matter, because matter doesn’t tell me why such and such a thing is what it is opposed to something else. What is, on the contrary, are individual things, such as tables, chairs and horses, and this is what Aristotle calls substances. Indeed, as he says, it is about such things that we make judgements; the table is brown, the chair is round, the horse is lame, and so on. Substance, therefore are the subjects of propositions. What something is made up of is its matter and form. The form of something tells is why it is what it is, whereas  matter is only what is formed.

Now, of course, there is a lot more detail in Aristotle’s conception of substance than this, but for our purposes this is all that we need to know at the moment. It is precisely this view, however, that is shattered by the new science. In the Aristotelian conception of the universe, since it is made up of individual substances, every substance has to have its own explanation, which makes his science extremely complex and unwieldy. Also, many of the individual predications of this science where shown through observation to be false. For example, Aristotle placed the earth at the centre of the universe and divided it into realms the mundane and the extra-mundane (basically everything on earth, and everything above the earth). The extra-mundane realm was immutable and perfect (not subject to corruption and change as in the mundane realm). This meant that everything in the universe was meant to rotate around the earth. Yet Galileo’s observation of the moons of Jupiter showed that there were rotations independent of the earth. Rather than observation describing a multi-differentiated universe, it demonstrated that that the earth was not at the centre, that there numerous planets, and that the universe followed the same laws that were few in number (three according to Descartes).[1]

Nature, therefore, was not made of infinitely many individual substances, but the one substance that Descartes postulated was made for corpuscles of matter that were infinitely divisible and whose movement and motion could be described accurately using mathematics. Thus any phenomenon we saw, such as the light of the rainbow, could be described in its own terms, as the movement and motion of such corpuscles.

At least in his physics, Descartes did not claim that this view was certain; that is to say, he put it forward as an hypothesis that worked. His defence of the new science was therefore practical. If we accept this view of nature, then we can see that we can solve the scientific problems that remained unanswerable, or had become impossibly complex in the old Aristotelian science. What he wished to achieve in his metaphysical writing, such as the Discourses and the Meditations, was a philosophical defence of this physics. How do we know (especially since the corpuscular view of nature is not something that I see through direct observation but is only a hypothesis) that the view of nature is true, that things really are what we say they are. In other words, that there really is a bridge from the subjective to the objective world?

This is where Descartes’ view of substance becomes more complex. For in fact there is not one substance but three: God, Matter and Mind. The physical hypothesis of corpuscular nature is first of all an idea and a mathematical one. Descartes’ scepticism, which everyone knows about is, is to find those ideas that we cannot doubt, but also more importantly, to separate our minds from our senses. For his argument is that we don’t understand nature first of all through our sense and then construct an idea, but our ideas is how we make sense of our senses. The idea is first. If the idea is first, then its legitimacy cannot be guaranteed by the senses that it explains. The first stage of Descartes’ method is to make us doubt the truth of our senses. This is a traditional part of philosophical scepticism and we can read the same arguments in Plato. How can I trust my senses when I know that they lie to me? How do I know that the whole of reality is not a dream? But the second stage of doubt is more interesting. For even Plato did not doubt that mathematical truths were an accurate representation of external things. But Descartes asks, how do I know that even the truths that I am certain of are really certain. For couldn’t a malicious demon simply put in my head that 2 + 2 = 4, when in fact it is 5? All I can be certain of is that if I am thinking something that it is I who am thinking it, for even I doubt that 2 + 2 = 4, then I cannot doubt that I am doubting it. Thus, as long as I remain within my inner space of my consciousness then I know what I am thinking is what I am thinking. When I think a chair I know that I am thinking a chair and so on. What I cannot know, however, is whether what I think is what the chair is in reality, or that what I think is the same as what you think. Thus we seemed trapped inside ourselves unable to get out each of us closed in our own worlds.

How does Descartes spring the trap? The answer is the malicious demon. He has to prove that this is only a thought and not a possible reality at all, and in fact the opposite is the case. This is because there is one thought which must have a reality that corresponds to it and that is the thought of God (which is the exact opposite of the malicious demon). I have the idea of God in my mind, but I cannot be the origin of that thought since I am a finite being and this is an infinite thought (not just in terms of its content, but what the thought is, its objective reality). The only origin of this thought must be God Himself who actually exists. We now see that a gap is opened up in ourselves to the outside (the outside in this case being God). This God, who is perfect and infinite and the highest reality), would not have created a universe in which there was no agreement between the material world and the inner truth of my consciousness. Thus Descartes’ argument is that the 3 laws that he discovered in his Physics are the continuous creations of God, and that God put the understanding of this laws into his mind, such that the one agrees with the other.

It might not surprise you that not every philosopher accepted this argument an one such was Hume. We might characterise Hume’s position as we don’t need to rid ourselves of scepticism in order to have a rational scientific understanding of nature and that Descartes went too far in his metaphysical speculations in order to do so. For Hume the source of all our ideas is perceptions. It is important to underline here that he doesn’t ask why that is so. He believes that it is impossible to for us to answer this question. It is precisely because Descartes thinks he can that the ends up with his unfounded metaphysical speculation. This limitation is very important for Kant, who is more Humean than he is Cartesian in this regard, and this is why he writes a critique of reason, which means nothing less than what are the necessary limits of reason, one of which would be that the only source of knowledge that we have is impressions. Perceptions themselves are divided into two: impressions and ideas. Impressions are what we might call sensations, like the colour blue that I am seeing now. Ideas are the concepts and thoughts that we have of this impressions. Ideas are only different in kind from impressions. An idea, if you like is an older impression, one that is less vivid and present than an impression. Thus, Hume would, say a blind man cannot have an idea of the colour blue because he has never seen such a colour. Simple ideas have their origin directly in impressions, but complex ones do not, because I can associated ideas in my mind without directly being present to the object, or even the object existing at all (think of the idea of the unicorn, which is made up the impression of two other objects, which are not present, the horse and horn). Hume’s question is whether there is a necessary order in my ideas as there is in my impressions (one impression comes after another one). In other words what is it that orders or groups my thought together. Why when I think of x do I also think of y?

The answer is that I associate the one with the other and there are three such principles of association: resemblance, proximity, and causality. If I see a picture of a fox, then I am likely to think of a fox, if I imagine a room in the university, then I am likely to think of a room next to it, and finally, if I think of stone dropping from someone’s hand, then I likely to think of falling to the ground. Now it is the last principle, cause and effect, which Hume thinks is central to how we think about human knowledge or understand of nature. The understanding, Hume, says is divided into two: relations of ideas and matters of fact. In the former, he is thinking of such things like logic and mathematics. For the first we do not have to go beyond the operation of ideas themselves (if you understand the one idea, then you understand why necessarily the other idea is associated with it, since if you understand bachelor you will understand why every unmarried man is one). But in ideas that are matters of fact this is not the case. Why do we believe that the sun will rise tomorrow, when we could equally believe the opposite. Hume is not arguing that we shouldn’t believe that the sun will rise (in fact he has good argument to think why we do), but there is no logical reason why we shouldn’t. The reason why we do is that we associate one idea with the other, the idea that the sun rose yesterday with the idea that the sun will rise tomorrow. We might think that we get to this second idea through an argument, where the statement ‘the sun rose yesterday’ is a premise. If it is an argument of this kind, then it could only be a relation of ideas or a matter of fact. It can’t be the first, since there is no contradiction in thinking the opposite, but it can’t be a matter of fact, because it is precisely that kind of argument I am trying to prove, so I appear to be going around in circles.

The answer must be that my conviction must have its origin elsewhere and that a belief is not the same a giving a reason or having a reason (indeed Hume will argue that our reasons have their source in our beliefs rather than the other way around). His answer is that the source of this belief is in our impressions rather than in our ideas first of all. It is because I have had the vivid experience of the sun rising again and again in the past. The belief that it will do so in the future is a habit and custom of the mind that I associated with the impression of I am having now. Thus when I see the see the dawn, whether directly or indirectly, I immediately associate it with the idea of the sun rising and I cannot help but do so because this custom or habit belongs to human nature intrinsically. A belief then is a particular vivid idea. Not as vivid as a direct sensation, but more vivid than a reason or a concept, and it is this that cause me always to associate x with y. Of course experience is open ended. It is perfectly possible that one day my belief will be disconfirmed rather than confirmed by experience.

I would say that Kant is more on Hume side than he is Descartes. In other words he takes it as given that our experience of the world is real. That we really do have sensations and that these sensations are external and not merely the product of minds. In other words, he is an empirical realist. Where he differs from Hume is that he is not convinced that causality is merely a habit of the mind. Of course this difference rest upon how one takes this ‘merely’. How necessary is a habit or custom? One might read Hume to say that it is pretty necessary. However such a necessity is only empirical and descriptive, which is how Hume limits his investigations, whereas for Kant causality is constitutive. In other words there wouldn’t be any experience whatsoever if we didn’t have this category. In other words, for Kant, if is not that we have experience x, and then experience y and then subsequently associate them in our minds through the principle of cause and effect, but that we would have any experience of x or y without it, even though, as he agrees with Hume, causality itself is not part of our actual experience. In Kant’s language, causality is a priori and synthetic. A priori, because it is not itself experiential, and synthetic, because it is actually doing some work, organising and making sense of our experience. The question, then, is what is the difference between the a priori synthetic, and a ‘custom and habit of the mind’. It is only by reading the Critique of Pure Reason that we shall discover it.

Works Cited

Hatfield, G., 2003. Routledge philosophy guidebook to Descartes and the meditations, London: Routledge.

[1] The three laws of bodily motion: What is in motion always continues to move; always moves in a straight line; a colliding body whose motion is greater will cause the motion to deflect, or if less carries that body with it. These three laws form the basis of Newton’s laws of motion.

Induction – Lecture 2

October 4, 2012

Last week we spoke about the difference between science and religion. We said that this difference could be conceptualised as one between belief and facts. The more, we investigated, however, what a fact is, the less certain we became of its status. Common sense might tell us that facts are just out there and we simply observe them and scientific theories are merely a collections of these observations. When we look at the history of science, however, it is clear that this is not how science works. What we take as facts are already determined by the way we understand and see the world, and our observations are equally shaped by this background conceptuality. In this lecture, we are going to investigate the problem of induction, and we shall see that we’ll come up against the same barrier again. Science is not just a disinterested observation of facts, but is already predetermined in some way or other to interpret these facts. Moreover the knowledge that science has of the world cannot itself be infallible, because of the very way that it interprets these facts.

Ordinarily we might think that scientific theories are obtained from facts through observation and this is what makes it different from observation. But what does it exactly mean that theories are obtained or derived from facts? How do we get from the one to the other? What we mean here is something logical rather than temporal. We don’t just mean that first of all there is a collection of facts, and then a theory, as though facts were just pebbles on a beach that we pick up. A theory, on the contrary, is supposed to tell us something about these facts before we have even discovered them. It is about meaning and context, rather than just what comes first or second in a temporal order.

What then do we mean by derivation when we speak about logic? We don’t have to go into the complexities of logic here but just the basic form since all we are interested is how theories originate from facts. Logic is based upon deduction. Here is a valid deductive argument, which comes from Ladyman:

All human beings are mortal
Socrates is a human being
Socrates is mortal. (Ladyman 2002, p.19)

1 and 2 are the premises and 3 is the conclusion. You cannot deny the conclusion if you take the premises as true. We can change the premises slightly, however, as Ladyman writes, and the deduction would be wrong.

All human beings are animals
Bess is an animal
Therefore Bess is a human being (Ladyman 2002, p.19)

What is important here is that it’s the form of the argument itself that is wrong. The conclusion does not follow from the premises even if one accepts them. Bess could be any kind of animal. What is positive about deductive arguments is that they are truth preserving. That is, if the premises are true and the argument is valid, then the conclusion is. The problem is that the conclusion does not contain any more information than the premises. It does not tell you anything more about the world and surely this is what science does.

From this is follows that if science is derived from facts then it cannot be done so logically, because logic cannot tell us whether a fact is true or not. If we know that there are true facts then we can logically relate them together (logic is ‘truth preserving’), but it is from experience whether we know that they are true. Take for example the scientific law that metal expands when it heats. It does not matter how many times that I repeat this it does not logically follow (as is implied below) that all metals will expand when heated:

metal x expanded when it was heated
metal y expanded when it was heated
metal z expanded when it was heated
All metals expand when heated (Chalmers 1999, p.44)

If scientific theories don’t come from facts logically, then how are they derived? The answer must be through experience itself; that is to say, inductively. What do we mean by induction? First of all the difference between deductive and inductive arguments is that in the latter the conclusion always goes beyond what is contained in the premises, as the example above shows. I can never be certain that all metals will expand when heated, because this is precisely what I assert when I move from a singular instances (this metal expands when heated) to the universal judgement that all do so.

How then can I adjudicate between a bad and good inductive argument in the way that I did with deductive ones? It would seem, through common sense, that I might be able to justify my universal judgements if I go through a number of singular observations. In other words that I observe a large number of samples of metal to investigate whether they do expand or not, and if I observe in this large number that they do, then I would be justified in asserting ‘All metals expand when heated’. Thus the laws of induction would be

1) The number of observations should be large

2) They must be repeated under a wide range of conditions

3) There should be no exceptions.

It is precisely for this reason that English philosopher and scientist Francis Bacon can up with his ‘new method’.[1] First of all this method is negative. The point is that we should avoid falling into bad arguments rather than coming up with new deductive ones. Bacon’s method is rules about how to practice science by avoiding some of the worst errors. These errors he called ‘idols of the mind’: that we tend to see order and regularity in nature when there is none, is the idols of the tribe; that our judgements and are shaped by our language and concepts rather than what we see are the idols of the marketplace; and finally that are views of nature can be distorted by our philosophical and metaphysical systems of thought are idols of the theatre.[2] From this follows the positive content of Bacon’s method is that we ought to make observations of nature that are free of these idols. It is from this mass of information that we should make generalisations rather than the other way around. This he calls the ‘natural and experimental history’. Thus it is important to understand that what he meant by observation is not just looking but experiments and it this emphasis on experiments that distinguishes the new method from the old Aristotelian one. It is experiments that preserve the objectivity of observations. First of all it allows them to be quantified and secondly that they can be repeated by others and thus tested as to their reliability. It is this data from experiments that are then put into tables. To use then example from Bacon of heat: first we have the table of Essence and Presence that lists those things that are directly part of the phenomena of heat; secondly, we have the list of Deviation and Absence, which lists those phenomena that are related to the first but have no heat; and then we have the list of Comparison, where features that have a quantity of heat are listed and quantified. The empirical method is one of elimination. Let us say I argue that the colour white is explanation of heat. Then I would check my tables and I would see that not all the phenomena that hot are white, or that some phenomena that are white are not hot and so on. White then could not be part of theory of heat. Through this process of elimination Bacon explained that heat was caused by the ‘extensive motion of parts’, which is not far from the modern kinetic theory of heat.

Bacon believed that one can discover the forms that made what we observed possible even though they were not directly perceivable. These forms where the direct physical cause of what we saw. This in the rejection of final causes where natural phenomenon where viewed as purposive.  Thus the explanation that stones fall to the ground because the earthly element seeks to fall to the centre of the earth. Teleological explanations such as these are only suitable for human actions (since humans unlike stones do have desires) but not natural phenomena. The ubiquity of physical causes is the major different between new empirical science of the 17th century and the old science of Aristotle’s era that had dominated the explanation of nature for so long.

There are, however, problems with induction. First of all what is the status of the non-observed forms that are the physical cause of what we observe. How can we make a leap from what is seen to what is not seen? It is possible to see how heat might be explained by Bacon’s method since in fact we can see the motion, but how would we go about explaining radiation? Also we see in science that there can be two competing forms that explain the same visible phenomena such as the two theories of light for example. Bacon does have an answer for the last problem. He says that we ought to set up two competing experiment that would test what we observe and we could see which was the more successful. But this already demonstrates what we might doubt about Bacon’s new method. In this case are not the theories themselves determining the experiments and not the what we observe? Bacon says that science is made from two pillars: observation and induction and that we ought to be able to observe nature without prejudice (the prejudices being the idols of the mind). This is perhaps what most people think that science is. We take many particular instances and then we generalise a law. Yet the problem is how we account for this mysterious leap from the particular to the universal. How many instances make a general law and if there is an exception does this mean that law is no longer a law? There are two problems with the principle of induction as Bacon describes it. One is that we might doubt that any observation is unprejudiced. This is not just in a negative sense as Bacon describes it, but also positively, that without a theory it is hard to know what one would observe in the first place. Secondly, we might worry about how it is possible to go from many observations to a general law. Just because X has happened many times before, how do we know we know that it will happen again? This problem of induction, as it is called, and was introduced by the Scottish philosopher Hume, has for many made naïve inductivism untenable.

Works Cited

Chalmers, A.F., 1999. What is this Thing Called Science?, St. Lucia, Qld.: University of Queensland.

Ladyman, J., 2002. Understanding Philosophy of Science, London; New York: Routledge.

[1] See (Ladyman 2002, pp.22–5) for this summary of Bacon’s method.

[2] As we can see, what Bacon sees as idols, we might see as unavoidable necessities and this precisely prevents us from accepting the inductive explanation of science.