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Presentation on theme: "HUME, KANT, HEGEL, SCHOPENHAUER"— Presentation transcript:


2 David Hume The Great Skeptic.
Denies the Rationality of Induction & Causality. Denies Science. Most “knowledge” is just custom or habit, not justified by reason.

3 Skeptic David Hume argues that almost all of our knowledge is acquired empirically. He is a skeptic about Induction. Most of our believes about the world are arrived at inductively- therefore Hume is skeptical about almost everything.

4 Induction and Scientific Knowledge
NEWTON: I have seen countless objects be released and fall down. ________________________________________________________________ 2) Therefore Any future object that is released will fall down.

5 Why do we think this is true?
NEWTON: I have seen countless objects be released and fall down. ________________________________________________________________ 2) Therefore Any future object that is released will fall down.

6 We assume past will resemble the future
We think this is true, because we assume that our experiences of things in the past will resemble life in the future. I have seen countless objects be released and fall down. ________________________________________________________________ 2) Therefore Any future object that is released will fall down.

7 Principle of the Uniformity of Nature
We assume what Hume called P.U.N. - Principle of the Uniformity of Nature The future will continue to resemble the past. The laws of nature that govern the world will continue to do so, as they have done in the past.

8 Science Science is based upon observation
We take observations and make inductions From these inductions we draw conclusions and rules Over time these rules become laws- laws of nature or science

9 How PUN works 10000 samples of water tested have had the chemical structure of H20 2) Given PUN ________________________________________________________________ 3) All future samples of water tested will have the chemical structure of H20

10 Induction 1) I have seen the sun set 1000 times in the west.
____________________________________________________________________ 2) Therefore the next sun set will be in the west.

11 Hidden Premise I have seen the sun set 1000 times in the west.
(Principle of the Uniformity of Nature) The future will continue to resemble the past ________________________________________________________________ 4) Therefore the next sun set will be in the west.

12 Substitute in any BLANK
1) _____________ has been observed _____________ times. 2) PUN ____________________________________________________________________ 3) ______________ will continue to be observed.

13 What is the justification of PUN, PUN!
1) Principle of the Uniformity of Nature The future will continue to resemble the past ____________________________________________________________________ 2) Principle of the Uniformity of Nature

14 Circular Reasoning 1) Principle of the Uniformity of Nature
The future will continue to resemble the past 2) Because in the past, the future has resembled the past. ____________________________________________________________________ 3) Principle of the Uniformity of Nature

15 Circular Reasoning You can’t use the same premise to justify what you are trying to prove. 1) God exist _________ 2) Therefore God Exist.

16 Hume’s Skepticism Hume claims induction does not give us knowledge.
Further, we aren't even rational in most of the beliefs that we hold. Hume questions Induction & Causality- the nature of cause and effect

17 Science is based upon Induction
Why is this important? The majority of scientific knowledge is based upon induction. If science is based upon induction, then our scientific theories unreliable. If induction is not rational, or if arguments based upon it are questionable, we become scientific skeptics.

18 1) If PUN is rationally justifiable, then there must be a good inductive argument or good deductive argument for PUN 2)There is no good inductive argument for PUN because such an argument would be circular 3)There can be no good deductive argument for PUN since PUN is not a priori- that is it requires experience to learn it. 4) So PUN is not rationally justifiable 5) Therefore, there is no rational justification for the beliefs that we form based upon predictions or generalizations.

19 Given that there is no Justification
Science is not rationally justified. All “knowledge” based upon induction is simply formed on habit and custom. What else do we know based upon induction- causality; cause and effect.

20 Causality No necessary connection between cause and effect.
1)Contiguity- the events are close together 2) Priority in Time- one after another 3) Constant Conjunction- one event following the other We form beliefs based upon inductions and causality from habit and custom- not reason.

21 Epistemological Theories
Foundationalism Coherentism Pragmatism

22 Foundationalism Theories that try to arrive at knowledge by means of a firm foundation. All knowledge is based upon certain basic truths. Rene Descartes is a Foundationalist.

23 Coherentism Claim that all of our believes must be compatible with one another. If I believe X, Y and Z; but if X contradicts Y & Z, then I cannot reasonably hold all three beliefs. If I believe that Life is sacred, That God had providence over Life and Death, and in the Death Penalty; Those beliefs are not coherent.

24 Pragmatism Pragmatic theories claim that, in a sense, truth is relative. Truth may be relative to: Individual Society Species

25 Definitions of Knowledge
JTB Theory Reliability Theory of Knowledge

26 JTB K= JTB Knowledge = Justified + True + Belief
That is all three conditions must be met to have knowledge.

27 Reliability Theory of Knowledge
The reliability theory states that knowledge should be acquired thru a reliable process. Examples of reliable processes are sight, hearing, touch, deduction, induction? Unreliable processes are ESP and guesses

28 Knowledge Vs. Justified Belief
If someone knows X, then X must be True. In order to have knowledge, it must be true. If your belief, X is true, and you are justified in holding that belief, then you know X. Again this is K= JTB. Yet you can have a justified belief, X and it could turn out that X is false- even though you were justified in holding that belief

29 Jim’s Justified Belief
CNN reports that a plane crashed into the Gulf of Mexico and all 100 passengers and crew died. If Jim is sitting on his couch and sees this report he is justified in holding the belief that all 100 people died.

30 Sara’s Justified Belief
If Sara is floating in the gulf of Mexico, (hanging on to her seat cushion)- she is not justified in holding the belief that everyone died. Rather she is justified in thinking that at least 1 person- herself, survived the crash. In fact, she might claim to know it.

31 Jim and Sara Jim might claim to know that everyone died as well, but he does not have knowledge because his belief is false. Sara does have knowledge because her belief is true. Truth is an important component in the equation of K= JTB. What is Truth?

32 Knowledge and Certainty
If knowledge requires certainty, then perhaps we should concede that many of our beliefs are not certain. If we need certainty in order to have knowledge, then we perhaps we cannot have much knowledge.

33 Theory of Truth Correspondence Theory of Truth
Pragmatic Theory of Truth

34 Correspondence Theory of Truth
A belief is true if and only if, it corresponds with something that exist in the world. My belief that a table is in the room is true, if and only if there actually is a table in the room.

35 Alfred Tarski Tarski: Snow is white, if and only if (iff); snow is white.

36 Pragmatic Theories of Truth
William James- Truth = useful to believe.

37 William James "The Will to Believe" is a response to the views of William Clifford stated in his essay, "The Ethics of Belief".

38 The Ethics of Belief (1877) William K. Clifford
Clifford contends that certain beliefs are epistemically unjustifiable to hold. We are acting wrongly when we hold certain beliefs. He thinks that beliefs that are not supported by sufficient evidence, or are not warranted by other beliefs should be abandoned.

39 James Denies the Ethics of Belief
James contends that beliefs can be held for other reasons, besides epistemic ones. He thinks that there are "passional" reasons for holding a particular belief, and that we can “will ourselves” to beliefs things that may be irrational- or not supported by any evidence.

40 God… Free Will…Idealism
James thinks that the existence of God cannot be proved or refuted by science. It is something that is open for us to believe in even though there is not sufficient evidence for it. Clifford would argue that such a belief is unjustified and wrong to hold; James does not.

41 “Will to Believe” James defines a hypothesis as a proposed belief.
Such a hypothesis may be: Live or Dead, Forced or Avoidable, Momentous or Trivial. When a hypothesis is live, forced and momentous then it is a genuine option for us to choose to believe in it.

42 “Genuine Option” When a hypothesis is live, forced and momentous then it is a genuine option for us to choose to believe in it. We must be capable of holding the belief We must think it is at least possible for the belief to be true.

43 Charles Sanders Peirce
Truth = whatever science determines to be true at the end of inquiry. Truth is relative. We do not currently know the truth. Irritation or doubt makes us question our beliefs.

44 Reasoning “The object of reasoning is to find out, from the consideration of what we already know, something else which we do not know. Consequently, reasoning is good if it be such as to give a true conclusion from true premisses, and not otherwise.”

45 Doubt leads us to Inquiry
“The irritation of doubt causes a struggle to attain a state of belief. I shall term this struggle inquiry… The irritation of doubt is the only immediate motive for the struggle to attain belief.

46 Knowledge = science With the doubt, therefore, the struggle begins, and with the cessation of doubt it ends. Hence, the sole object of inquiry is the settlement of opinion. Scientific Inquiry will result in Knowledge

47 Immanuel Kant The world beneath perception.

48 A priori vs. A posteriori
Kant argues that not all of our knowledge arises from experience. Distinction between empirical, a posteriori knowledge and pure, a priori, knowledge. What makes the one differ from the other is that a priori knowledge is universal and necessary. Empirical knowledge cannot give us anything that is universal and necessary.

49 Causality We experience A then we experience B. We conclude that A follows B. After experiencing this course of events many times we might conclude that A is always followed by B. Scientist do this all the time, They conduct a number of experiments and conclude that something is necessary.

50 Water always boils at 100 Celsius.
A: Pure water is heated B: it begins to boil at 100 Celsius. The scientist does not say that water does this occasionally or sometimes, but that it always boils at 100 degrees. This is a universal statement. We do not have to boil every sample of water to know that every sample of water will follow this rule. (Or so Kant maintains)

51 Structure of the Mind According to Kant, what makes scientific knowledge possible is not my experience, but the way my mind structures the experience. My mind determines how I will experience such things, Because of the structure of the mind, it follows that those experiences are a priori and necessary.

52 Causality is Necessary
According to Kant my mind is not a passive agent, but rather plays and active role in knowledge. It does this thru the categories of understanding. These categories are how humans necessarily perceive the world. Causality is one category of the mind. The mind necessarily perceives causality, according to Kant….

53 Phenomenal vs. Noumenal
Phenomenal- the world as we experience it thru our perceptions Noumenal- The world how it is beneath or beyond our perceptions.

54 The world beneath our Sense
According to Kant, our phenomenal view of the world- how we perceive the world is shaped by our mind and our senses. The noumenal world- how the world really is, unperceived, is impossible for us to know.

55 Phenomenal Vs. Noumenal
This claim regarding how we necessarily perceive things is similar to the argument that, as humans, we have certain sensory apparatus- we have eyes, ears, a nose and a sense of touch…

56 Ours Senses color Perceptions
We perceive the world in a particular way because of these things. The board appears white- to us If we did not have eyes, then it would appear differently to us. How it really is, apart from our perceptions of it is unknowable to us. In the same way, the noumenal world is beyond the scope of human knowledge.

57 Georg Hegel Absolute Idealism-
Denies Kant’s notion of a Thing in itself, or the noumenal. All reality is the expression of thought or reason

58 Noumenal does not exist
1) If an object is unknowable, then it is unthinkable. 2) The Noumenal is unknowable. 3) Therefore the Noumenal is unthinkable. 4) If an object is unthinkable, then it does not exist. __________________________________ 5) Therefore the Noumenal does not exist!

59 Arthur Schopenhauer Held that the world is structured according to will, that nothing can bring meaning to our existence.

60 Life and Death Schopenhauer called himself a Kantian and despised Hegel. He formulated a pessimistic philosophy that gained importance and support after the failure of the German and Austrian revolutions of 1848. Schopenhauer's health deteriorated during the year of He died of natural causes on September 21 of the same year at the age of 72.

61 Life is negative Schopenhauer argues that the nature of human existence is such that it is impossible to experience to have positive experience. He claims that life is pointless because our choices of ends or goals are entirely arbitrary.

62 Can’t fulfill our desires
He claims that what we consider good is simply those things that aid in the satisfaction of our will, (our desire) and those things that are bad are those which get in the way of our satisfaction of our desire.

63 Minimalism He says that it is impossible for our desires to be fulfilled because the fulfillment is transitory- the moment our appetite is sated another desire appears and we are left with nothing. This view is similar to Epicurus.

64 Desire is Negative That is why he claims that desire is something negative. Schopenhauer’s main point is that nothing can really ease our suffering in this existence except death.


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