Descartes, 1596-1650

I. Founder of "modern" philosophy ("Cartesian" is the adjective from "Descartes".)

 A. Difference between medieval (start with what we know and ask how it's possible for us to know it) and modern (start with how we know and ask what we can know).

  B. Descartes understands himself to be engaged in an anti-sceptical project - put knowledge on a firm footing...Distinguish between the Justified belief, and the mere belief.

   C. "Justified" is a moral term. It is wrong to commit yourself to unjustified beliefs.

II. Foundationalism (Descartes is a foundationalist, but note that there are many different sorts of foundationalist. What makes you a foundationalist is that you think that...

A. There are basic beliefs that do not require further justification. 

B. Every justified belief is or can be traced back to a basic belief of this sort.

-- Modern Philosophy largely a debate between empiricists and rationalists --

III. Rationalism (Descartes' brand of foundationalism) 

A. Turn within, knowledge arises from the reason

B. Knowledge does not arise from our senses or experience which are changing and different to different people. (The wax experiment)

IV. Knowledge -- truly justified beliefs to which it is legitimate to commit ourselves -- for Descartes means...

A. certainty. 

B. Indubitability. If a proposition is doubtful, if we can possibly doubt it then we can't know it, and we shouldn't commit ourselves to believing it. 

C. Quest for Knowledge following example of mathematics

 -- Two reasons for accepting propositions --

 A. intuition (just cognitively "see" something indubitably)

  B. deduction (move from indubitable premises through indubitable principles to indubitable conclusions).

 V. So...  What can we know indubitably?

 A. History?

 B. Memory?

 C. Other minds?

 D. This room?  Your body? ("Extra-mental reality")
  1. dream
  2. mad scientist
  3. evil genius

E. 2+2=4, laws of logic?

-- We seem to have thrown everything away. Are we stuck with total skepticism? How can we get things back?

I. There is something I can intuite immediately and with certainty: I think -------> I am. Cogito ergo sum!

  1. Can I doubt it?
  2. No, I still am if I doubt?

The Foundation!

(We haven't gotten far!)

II. God! (We can deduce the existence of God with certainty.)

 A. My mind is full of ideas , and I cannot doubt that they're there. 

 B. Most of them I could have generated on my own.

 B. But not my idea of  God - I have in my mind the clear conception of a perfect, an unlimited being.  

    1. Such an idea could not have been generated by me, or by ANY limited being. 

     2. So it must have come from God. So there must be a God!

     3. But couldn't the critic say that we just negate our limitations to produce the idea of God? 

     4. Descartes responds, No.  Without the idea of God we couldn't recognize ourselves as limited.  Idea of perfect must precede our recognition of ourselves as limited

    God exists!

V. A good God would not allow us to be systematically deceived.

 A. We might make the occasional mistake through our own fault, but....

 B. No systematic deception.  We can trust in those things that seem so sure - 2+2=4, external world, body - because we've ruled out the hypothesis of the evil genius.

VI. Problems - Note that Descartes has set himself a very difficult task. Certain foundation > certain arguments to certain conclusions

 A. Is the proof for God indubitable?

-- Suppose we allow that there is a God. Even still there are difficulties ---

 B. God allows evil.  Can we be certain He'd draw the line at you being systematically deceived?

 C. Deception might be good in some case and maybe that case is you right now.

-- And then there's possibly the worst problem, which goes by the name of the "Cartesian circle" --

 D. At outset we doubted laws of logic! 

    1. But we assumed logic to get to conclusion. 

    2. So, at least in the case of trusting the laws of logic, Descartes begs the question (That is, he assumes what he's trying to prove. That's bad!!!).

VII. Dualism (Cartesian dualism)

-- Dualism vs. materialism (you're just body)(nowadays often called "physicalism")...option 3? You're just mind.

 A. What are we really?  Thinking things

 B.   We are mind (an immaterial substance) and body (a material substance). Mind is the real and essential YOU. Rather like Platonic dualism.

  Two fundamentally different kinds of things which somehow interact.

 C. Why should we believe we're really composed of 2 elements? (vs. materialism)

  1. We have to think of them as separate, because we justify our belief in them in different ways: We intuit mind, we must deduce body

  2.  The thinking part (mental phenomena ) has different characteristics from the physical part (body phenomena).  Irreducibly different. Mind-talk and mind-concepts cannot be reduced to talk or concepts about body.

a. Mind is indivisible vs. divisible body (Descartes' favorite distinction) You can't cut up an idea with a scalpul.

b. Mind is private vs. body, in principle, is public. Only I have immediate access to my mental states.

D. The big problem -

  1. interaction? How can two absolutely different kinds of things, one material and one immaterial, interract causally? It just seems impossible.

  2.  Descartes suggests they interact at the very sensitive pineal gland. Doesn't solve the problem, since the pineal gland is body.
 

John Locke 1632-1704 

EPISTEMOLOGY :  British Empiricism

British empiricism takes a fundamentally different approach from Aristotle and Thomas Aquinas. Aristotle and Aquinas would have said we experience the physical object in question.   For Locke what we actually experience are ideas. The ideas we have of sensible things are caused by the extra-mental objects out there in the world outside our minds. But what we are experiencing is the "movie" playing in our minds, projected by that extra mental world.  Ideas are copies of what's out there.

I. We are tabula rasa (blank slates) before we start having experiences.

 A. Ideas come from sensation (sense data) and reflection (mind's thinking about its own operations)

 B. No innate ideas (vs. Descartes - God)

  Even basic truths of logic come from sensation and reflection

II. Simple and complex ideas

 A. simple 

1. single, unified eg. sense data -- pink,
   cold, or reflection (the latter come from mind, not senses) --fear. 

2. Received passively.

 B. complex

1.compound, put together by the mind. 

---So we can go beyond the bare deliverances of our five senses because the mind can actively work on the sense data.---

2. the mind can actively... 

a. join -- hand (pink, cold, this shaped etc. ...)
b.  compares -- this thumb is bigger than that
c.  abstract -- (man) hand

III. Primary and secondary qualities -- A Quality = a power in the object to produce an idea in the mind.

 A. primary qualities produce ideas which...
  1.... correspond to the way things are in themselves.
  2. Primary qualities are described in mathematical terms
  3. Our ideas from primary qualities reflect objectivity, so we can all agree on them.

 B. secondary qualities produce ideas which ...
  1. ...don't reflect how things really are
  2.  Sense data are caused by this extra-mental object, but the idea which is produced is not like the extra-mental object because the info from the object interacts  with the perceiver -
   eg. cold, red exist only in the mind of the knower
  3. So with our ideas of secondary qualities there is no objectivity.

 C. Distinguish between appearance and reality. Reality will be what is ...

   --mathematical
   --what science can give us

D. Worrisome practical consequences. (Note that Locke himself does not draw these conclusions, but they seem to follow from his analysis of primary and secondary qualities.)

1. Aristotelian would have said the careful observer can come to know the world vs. Locke, whose views seem to entail that it is only the Scientist...the guy with the measuring instruments...who can really tell us about reality.

2. Atomism is making a comeback and Locke's view could lead to reductionism -- the world is reduced to atoms, it's the atoms that are really real. 

IV. "Substance"

 A. Qualities must be in something, holds them together

 B. But the something has no qualities - it can't be
  perceived, described or thought.  It is just a "something I know not what."
 
 
 

Berkeley 1685-1753

I. Locke
 A.  What we know are ideas
 B.  Ideas caused by qualities in the thing
 C. Primary and secondary qualities
 D. Substance

---------------------Berkeley's goal is to save our world of experience-------------------------

II. Idealism: As empiricists we ought to say that what we can know and what there is is what we can experience 

(-- a qualifier -- unless reason proves that we should believe in something more.)

 A. What can we know of this physical object?  

    1. Only what we perceive (consciously experience ). 

    2. Therefore physical reality is what is perceived. To be is to be perceived.  Esse est percipi. 

    3. What is this physical object but a combination of the ideas we have of it?  

    4. No gulf between material and mental...everything is mental.  

    5. If it were the case that absolutely nobody were perceiving an object it would not exist.

B. Four Arguments in favor of idealism (note that 2-4 are directed against Locke's empiricism in particular):
   

    1. You can't even conceive of anything as existing unperceived by any knower.
   

    2. Locke said ideas related to secondary qualities exist only in the knower (cold, red, etc.).

        a. But it is impossible to conceive of a thing with primary qualities without the secondary qualities.

        b. If secondary qualities are "all in the mind" then we ought to say that primary are, too.

   3. Locke said our ideas are copies of things out there in extra-mental reality.  

        a. Absurd!  To know that something is a copy of some original you have to know the original. 

        b. But Locke says we don't have access to the original. 

        c. So we can't say that our ideas are copies of what's out there.
   

    4. What about Locke's Substance? Locke said it was that which underlies and unites the qualities in a physical object, and it is the qualities that give us ideas.  

        a. Locke admits that, not only can we not perceive it, we can't even conceive of it.  

        b. So Berkeley concludes that it's a meaningless term.  

        c. But substance was an important part of the makeup of individual, physical objects. Without underlying metaphorical glue no reason to believe physical objects exist at all.

III.  A Problem for Berkeley -- Is reality subjective?   Solipsism? (All there is is just me and my movie?)

 A. No, my experience shows me that it can't be that I am alone with my ideas because the  ideas I have ...
  

    1. ...seem to come from outside of me.  (So I know I'm not causing them.)  

    2. ...relate to one another in an orderly way which I know I'm not imposing on them.

    3. And, especially telling -- I don't have to be perceiving things for them to continue to exist -- behave in orderly way without my perceiving them. Let's light a candle, leave the room, and come back an hour later.

 B. So where does the movie in my mind come from?  God!

 C. What there is is God's mind and His Ideas and our minds and our ideas.  It's all mind stuff from top to bottom.
  

    1. Gets rid of "substance"
    

    2. Saves world of appearance

IV.  Solves problem with Cartesian dualism -- yes you have consciousness (mind) and a body, but the body is mind-stuff, too. 
 

Locke's Political Theory

I. Q: Where does government get its authority? A: The consent of the governed! 

1. "Contract Theory".

2. Those of us who are big on freedom and rights and personal responsibility are going to like the sound of that. But let's be careful. You can run this justification different ways.

II. Hobbes' (1588-1679) Political Theory

A. Hobbes' version of the "State of Nature"  (The human condition without government)

 1.  We desire power and stuff . We have Equality and freedom -- equal ability to do each other damage.

 2. War of all against all

 3. No power to enforce moral or legal rules, so there are no rules, chaos. 

-- Note that Hobbes talks about a "natural law" but it isn't the sort of natural law that Aristotle and Aquinas talked about. It's just about how we can satisfy these basic desires for power and stuff. 

 4. Anybody can do anything to you. No natural rights to life, liberty or possessions (no morality outside of society).

 B. People make a contract. By mutual consent they agree to...

1. Give up equality and freedom.  

2. Turn over all their power to a sovereign (ruler) in exchange for order.  

3. Sovereign (to do the job) must have almost absolute power.  

a. "There can be no unjust law."  State can do whatever it wants to you.

b. There could be a "bad" law in the sense of not doing the job of keeping order, but even that MUST be obeyed.

c. Can you opt out of the contract? Well, yes, but then you're in a state of nature vis-a-vis the State and everyone else, and that means they can hunt you down like a dog and kill you.

 III.  Lock's State of Nature

 A. Reason can tell us that...

1. there is a God who orders human existence. 

2. There is a natural law -- of the robust Aristotelian sort -- which we can recognize, which shows us proper rules for behavior with or without/state.

 B. Reason teaches that equals must be treated equally. 

1. I do not want to be harmed, enslaved, or killed  

2. So I see that I must not kill or harm others.

3. To put it another way,  we all (even without state) have natural rights.  Life, liberty, property.

C. Right to property, for example,  is not a function of having a government.  God gives world to all, but I make something my own by mixing my labor with it.

--So Locke's state of nature much more benign than Hobbes'. But here's the problem with it...--

D. Everybody's on his own with respect to ...

1. recognizing the moral law and figuring out how to apply it to the specific situation

2. judging whether or not others are obeying the moral law 

3. executing the laws (i.e., seeing that they are carried out.) This includes an individual right to punish wrong-doers. Natural law includes right of each individual to punish anyone who transgresses. So...   

IV. So Locke's state of nature is inconvenient in that it lacks...  

 A. Known legislators who could establish laws that everyone would recognize as binding. Laws which are a specification of the natural law.

 B. Known and objective judges

 C. Recognized agents with power to enforce law

V. We agree to form a state.  We make a mutual contract.

 A. We give up individual power to determine, judge, and enforce laws to government. [Difference from Aquinas - state chosen vs. just sort of grows naturally as an intrinsic element of human society]

--N.b. Assuming we divide up these three jobs, how many branches of government should we have? --

 B. We don't give up our natural rights -- we can't, they're inalienable.

C. So the proper authority of government is limited by 

1. Our natural rights and ...

2 The jobs we've turned over to it to do.

VI. Against Hobbes! 

 A. Power of government limited. NOT ARBITRARY! Role of government is to supply what was lacking in state of nature in order to effectively enforce edicts drawn from natural law.

 B. For example, Government may not take your property without your consent

  1. taxation?  You consented

  2. American revolution!

VII. Problem with Consent?

 A. Did you give consent?

 B. tacit consent?  Just by living here and enjoying goods of ordered society?

  Hume's analogy of the ship.  (Suppose you're born on a ship at sea. Have you given your tacit consent to whatever the captain and crew want to do just because you don't jump overboard.)
 
 

Hume 1711-1776

 Review point about pragmatism  -- For Plato and Aristotle and most of the Medieval Philosophers...

--- Start with what we know and ask how.

--- Point of Philosophy is to lead the good life - If conclusions can't be lived with reject them.

I. Not Hume! He embraces radical empiricism.  As opposed to ...

 A. Locke. All knowledge begins with experience, but we can go well beyond what experience (especially the senses) gives.  For example, we must believe in a material substance and God.

 B. Even Berkeley says we have to believe in God.

II. But Hume says that ALL ideas are copies of impressions i.e. experience - either sense experience or  experiences of my own mental state. 

--- So, we can properly make two sorts of judgments...

  A.  About "the world", the way things are -- This is based on what we experience.

  B. Relations of ideas, ways ideas group themselves or ways we've chosen to talk -- For example, All bachelors are unmarried. This is just about what "bachelors" means in English. 

III. Causality? (Ordinarily we look at whole world as a system of causal relationships - if we cannot have knowledge of causality, then we can't know much!)

 A. Define "cause." 

    1. Not just a constant conjunction -- event A consistently followed by event B.

    2. But rather a necessary connection. -- event A produced event B.

---We are not justified in believing in causal connections!!! ---

 B. There are two sorts of reasons we might appeal to to justify our beliefs in causal connections.

        1. A Conceptual connection? 

            a. Does the idea or concept of the cause "contain" or entail the idea of the effect? 

            b. No. We can think the apparent cause without thinking the apparent effect.   

            c. For example, We can think fire without thinking it burns cotton.  We can imagine that the cotton will turn into a parrot.

         2. But don't we Experience the cause causing the effect?  No!

            a. We experience only a constant conjunction.

            b. We don't experience anything else, so we don't experience a necessary connection.

C. (Another way of putting the problem.) The future may not resemble past.

      1. Claiming a necessary causal connection between A & B involves making an assumption which is not justifiable.

      2. B will follow A, i.e. the future will be like the past

           a. The future can't be sensed.

           b. It won't do to say, well "It always has!" since that's  ..."in the past!"    

 D.. How do we come to believe in necessary causal connections?

  1. It's an idea.  Must be the copy of an impression.

  2. After enough experiences of conjunction (B following A) the mind just moves inevitably from what we call "cause" to what we call "effect."  [movement=determination of mind]

   a. I have an impression of this determination of mind [necessary movement from A to idea of B]

   b. My idea of causation is a copy of this impression.

   c. So "causal connection" is not in things - it's in my mind.

 E. Conclusion:  

    1. When we go about our lives we do make all these unjustified assumptions.  We have to.  

    2.. But as philosophers - when we're being reasonable - must be skeptical. 

--- Note that Hume has made it very explicit that there is a great divide between the practice of philosophy and living one's normal life.--

IV. Problems with this view of causality.

 A. Where does this leave science?

    1. Isn't the practice of science a prime example of respectable reasoning?

    2. But science talks about

        a. causation and ...

        b. things in universal terms. (If I say that X happens every time, then I'm making the unjustified assumption that the future will be like the past.)

    3. So science falls on the sloppy, everyday side of the great divide.

 B. Hume's position on causation is self-contradictory. 

      1. His conclusion is that as philosophers we must maintain a skeptical attitude towards causal claims but...

      2. His starting point was to make a causal claim. All ideas are produced by impressions. 

      3. He even makes a causal claim to explain how we get our false idea about causal claims!  
 

Hume continued.

-- More conclusions  of Hume's radical empiricism --

 I. What about Locke's substance?  Substance is the underlying unity that...

A. binds qualities together .

B. means thing exists objectively over time (i.e., it's not just qualities as perceived by us.)

C Hume will say there is no substance.

 II. No extra-mental objects. (Note that Hume is not concerned to be consistent and systematic. Elsewhere he will, of course, assume that there are things outside of his mind.)

III. Logic and math.

 A. ~(A + ~A), 2+2=4  true always and everywhere.  We don't learn them through our senses.

 B. Yes, they'll be true tomorrow, but they are not truths about the world.

 C. They're truths about relations of ideas, i.e. they're descriptions of how human being happen to think, but we have no reason to suppose that our thinking reflects reality. (Radicalissimus!)

 IV. Self

 A. Descartes said "I think, therefore I am."

 B. Hume.  We don't experience any "I".  All we experience is a series of impressions.  We are just bundles of impressions.  No spiritual substance.

Hume on God

C. So, We see a house (effect) , we conclude there must be an architect/builder (cause). 

D. Analogously, Universe (effect)  implies that there must be a God (cause).

II. Hume provides a series of criticisms of this argument. 

--Note that, for the sake of argument, he will often grant his opponent's assumptions in order to show that the design argument is mistaken even if these assumptions are allowed.

A. Well, Hume says we're not justified in believing in any sort of causation to begin with.

B. Suppose we do allow arguments moving from effect back to cause.

    1.We believed in the architect because we've observed a constant conjunction,   architect ---> house.

    2. We have not observed a constant conjunction, God ----> universe.

C. Even if we allow that some things are caused, we could just say the universe as a whole is not the sort of thing that requires a cause. 

    1. It has always existed and been going on the way it's going on. 

    2. The things that exist today were caused by the things that existed yesterday which were caused by the things that existed the day before, ad infinitum, so there is no cause.

---Someone like Thomas Aquinas would say we need a Necessary Being ---

D. We observe only a tiny part of the universe, so can't draw any conclusions about what the whole is like, and so can't move back to a cause.   

---Someone like Thomas Aquinas would say that we have to use the evidence to hand.  As far as we know there are ubiquitous laws ---

E. And even if we say there's a cause for the universe as a whole... Certainly not the sort of cause we identify with God

    1. an infinite cause? We observe only a finite effect, so can't posit an infinite cause.

    2. The problem of evil! The universe is so nasty that it is unlikely that it could have been made by God.

        a. Maybe it was made by a committee.

        b. Maybe it was made by an infant diety. 

---Someone like Thomas Aquinas would say that the universe is really good!!! There's an answer to the problem of evil.---

 Hume on Morality.  "It's wrong to torture small children for fun."

I. We do have some sort of ideas about right and wrong, good and bad, ought and ought not.

A. Do we have any impressions of "right" or "wrong" in the thing or action? No, right and wrong are not observable properties.  

B. Therefore right and wrong do not exist in the actions, and we don't get our ideas of right and wrong from observing actions.

C. These ideas come from our impressions of our sentiments (feelings) as observers.

II.. A problem.  The critic may say that Hume's position renders morality selfish and arbitrary. 

--- Hume says, No! --

  A.  Our feelings won't just be about self-love, nor will they be arbitrary.

  B. We naturally like what's useful to society (i.e. what promotes general happiness)
   
  C. This will not satisfy the believer in objective morality.

       1. What if sentiments should differ?  From society to society?  From person  to person? Jeffrey Daumer?  

        2. More importantly, even if we do all happen to agree, it's still just a matter of taste.           

        3. No objective right is wrong.  Relativism!
 

Kant 1724-1804

I. The problem:  Neither rationalism nor empiricism does the job.

 A. Rationalism:  

    1. spinning airy webs, internally consistent but mutually exclusive. , 

    2. with no appeal to experience there's no way to test which is closer to reality [science marches on]

 B. Empiricism:  crucial ideas for human living just drop out morality, God, Freedom, Self, Science!

 II. "There can be no doubt that all our Knowledge begins with experience...but...it does not follow that it all arises out of experience."

III. Divisions of Knowledge

 A.Sources of knowledge:  

1. A priori -- what we can know prior to experience. We don't get it from experience.

2. A posteriori -- what we get from experience. "Posterior" to experience.

 B. Two types of knowledge: 

1. Analytic (is about concepts, language)

2. Synthetic (is about the world)

 C. All analytic truths are known a priori.   

D. Most synthetic truths are known a posteriori. (Hume would have said all.)

 E. Kant:  No, there are synthetic a priori truths. For example,  "Every alteration must have a cause." It tells you something about the world, but you did not learn it from experience. 

 IV. Kant's "Copernican Revolution" -- Change the position of the perceiver.

 A. Previous thinkers say mind conforms to objects.

 B. No!  Human mind actively structures information coming in.  Objects conform to mind.
    1. We have "lenses" in our minds which structure the data.     

    2.Noumenal (outside the mind) vs. Phenomenal (what we experience) Worlds.
          (Analogy: Dark glasses in Oz make it so that anyone who sees the "Emerald" City, sees it as green.)

 C. Categories -- among the "lenses" are...
  1. Causation
  2. Space and time
  3. Mathematics

 V. Now we can get back Freedom, morality, self, God - these are not given by experience, but that doesn't mean that they aren't there in the noumenal world.

 We recognize that we are moral beings, we have to act, make moral choices in the world, so we must have...

A. Freedom (If we aren't free we can't be responsible moral agents)

B. A self that exists as a unified thing over time. I am responsible today for what I did yesterday.

C. God. Moral agency is incoherent if the outcome for the wicked and the virtuous is just the same. We have to have God as the final arbiter of justice.

VI. Problems? 

A. Solipsism? (It's just me an my phenomenal world)  [To my knowledge,Kant doesn't have an answer.] 

B. Why suppose there's a noumenal world at all? Maybe we're all share the same phenomenal world, but there is no noumenal world. (Sounds a bit like Berkeley)  More important historically -- Fichte (1762-1814)  Sets up German Idealism.

C. Kantian answer -- there must be something which causes our experience of the phenomena.

D. Fichte's response -- But your claims about causation are inherently contradictory; the claim that data comes in from the noumenal world and is structured by the mind is a causal explanation, but you have said that causality "exists" only in the phenomenal world.

Kant: Ethics

 I. The only intrinsically good thing is a good will. ("Will" = the mental faculty by which you make choices.)

 Happiness?  Intelligence?  etc. No, these things are good only when coupled with a good will.

------------------WHAT'S IMPORTANT IS MOTIVE (not consequences). Act derives moral value from motive. ---------------------------

 II. Good will acts from duty: deontological

 A. Not from self-interest (merchant)

 B. Not from  natural inclinations (the philanthropist vs. the misanthrope)

III. Duty = The correct principle which must be both reasonable and universal. (Logically consistent and applicable to everyone. I must not make an exception of myself.)

IV. Categorical Imperative

 A. First form:  "Act only on that maxim whereby you can at the same time will that it should become a universal law." 

1. You have to be able to consistenly will that everyone could do this.  (Aka, "universalizing your maxim")

2. You have to be able to will that anyone could do this, even if you were in a different position in the situation. 

3. Note that he is NOT saying, "If you do this, other people really might do it." That would be looking at consequences. No, he is just asking you to do a thought experiment about what you can consistently will.

4. Examples --

  1. Making a promise with the intention of breaking it.
  2. Cheating on Test #4.
  3.  Failing to help someone in need. (Not a logical contradiction like the first two, but you still can' consistently will it.)

 B. Second form:  Treat people as ends in themselves, never only as means to an end. (Lady at the McDonald's? All good, since all parties agree and are pursuing their own ends.)

 V. Problems with CI

 A. First form  

  1.  We can generate contradictions by universalizing apparently innocuous or virtuous behavior.

  2. Notoriously difficult to formulate rule, so we can see exactly what it is that we are universalizing.

   a. What, exactly, am I doing?

   b. How general or specific should it be?
    1.general?  implausible consequences
    2.specific?  applies only to me

  3. Fanatic can universalize any crazy rule

 B. Second form

  1. No help in resolving a conflict of claims. 

  2. Absurd consequences? Never use people as means to an end? "Do no injustice, though the heavens fall."