LOGIC: The Theory of Knowledge

1. LOGIC: The Theory of Knowledge • Epistemology: means by which knowledge is acquired

2. How Do We Determine Truth? HOW DO WE KNOW WHAT WE KNOW? WHAT IS RELIABLE? WHAT IS TRUTH?

3. Ways We Know • Authorities • Parents • Church • Teachers • Leaders

4. Ancient Greek Philosophy • Sophists—doubted the possibility of discovering anything that was really true • Protagoras said, “Man is the measure of all things.” • Gorgias proclaimed, “Nothing exists, and if it did, no one could know it, and if they knew it, they could not communicate it.” • Taught how to “get along” w/o certain knowledge (training) • How to speak well and convincingly • How to win arguments • How to succeed

5. Socrates • Worried about “schools for success” (which seemingly resemble many present-day educational institutions.) He believed schools... • Did not possess genuine knowledge and yet presumed to instruct people in worldly success • Teacher and student might be doing the wrong thing since they did not have “positive knowledge.” • Being able to speak well, convince people, be a leader etc was invalid unless they knew what to speak about, or convince people of or where to lead them. (Truth) • If their opinions were wrong, they would lead them down a road to utter ruin.

6. Plato • One could act only on the basis of the truth. And he tried to construct a theory of knowledge • Knowledge consists of “the apprehension of those aspects of the world that never change, never alter” • World contained constituent elements called ideas (truth) or forms (geometry, ideal beauty).

7. Logic?

8. The Problem • (a) Rover is a dog (stuffed dog) • (b) Fido is a dog (wolf, coyote) • (c) Spot is a dog (pet) • If Fido and Rover and Spot are all different animals, what are we saying about them? • Each have something in common • Each have a common classification • But what is the general term “dog” refer to? • If we pointed to Rover, Fido, and Spot, would that make clear what the general term “dog” referred to? • PLATO SUGGESTED THAT OUR ORDINARY STATEMENTS INCLUDE THE USE OF GENERAL TERMS, AND THAT IN ORDER FOR OUR ORDINARY STATEMENTS TO BE MEANINGFUL, ONE MUST KNOW WHAT THESE GENERAL TERMS SIGNIFY. • PLATO INSISTED ONE MUST DO MORE THAN MERELY POINT TO VARIOUS PARTICULAR THINGS AS EXAMPLES.

9. A Possible Solution • Discover the meanings of our general terms which are different than our experiences by • Universals “meaning of general terms” • Only if we know what is required for something to be a dog, can we tell if Rover falls into this classification • WE COULD NOT KNOW THESE UNIVERSALS THROUGH OUR SENSE EXPERIENCES • Platonic ideas (ideal--abstract theories/ideologies)

10. Possible Solution: part II • Dialogue entitled Meno claims • “we cannot acquire knowledge through learning” • One could not tell that something was true when one learned it unless one already knew it to be true or one cannot learn what one does know since one already knows it • All the knowledge of forms, or universals, is already in our minds—we only have incidental effect of jarring our memory (recollection) • Where did they come from? • They are already within us from birth—which existed in the “soul” prior to one’s birth (Platonic ideas) and is forgotten at birth and must some how regain consciousness of the knowledge that is already there.

11. Socrates’ Kinds of Knowledge • Visible Knowledge—acquired through the senses (images, appearances) • Intelligible Knowledge—ideas and abstractions (geometry) • Highest Level—occurs when one knows the Platonic idea, in the sense of being fully aware of it in one’s mind, and understanding its nature. The AHA moment.

12. Plato’s Allegory of the Cave • Humans live in an underground cave which opens toward the light • They have been here since birth with their legs and necks chained so they cannot move and can only see before them being prevented from turning their heads. • Above and behind them is a distant blazing fire and between them a wall where men pass carrying all sorts of materials • They see only the shadows on the walls • The truth would literally be nothing but shadows of the images • What would happen if the prisoners were released and could turn their heads? • Firstly, they would experience pain • Secondly, the glare would distress them • Thirdly, he will be unable to distinguish the realities of the shadows he previously had know • And then what if someone said what he say before was an illusion • He would be confused and when he goes toward the light he will experience pain, confusion, and blindness to the light • He will want to turn back to the illusionary darkness for safety • He will be required to grow accustomed to the sight of the upper world through shadows, reflections in water, the objects themselves, and finally the sun itself.

13. Meaning of the Allegory • The prison house is the world of sight • The light of the fire is the sun (truth) • Journey upward is the ascent of the soul into the intellectual world

14. Think about This • Modern Day Cave Allegory • http://faculty.frostburg.edu/phil/forum/TheCave.htm • Allegory of the Cave

15. Philosophers into Kings • Train them to RECOLLECT the knowledge that is within. To study the relationship between things. • Use of Reason (relationship of things) • Arithmetic • Geometry • Astronomy • Harmonics (science of musical sounds) • Dialectic (formal system of reasoning or thought)

16. Descartes: Theory of Knowledge • Descartes’s Test • If there is any reason for doubt, then the entire category ought to be treated as doubtful and unreliable • If we inquire into the truth and find evidence lacking, then our most cherished beliefs could be false. • We are capable of discovering absolutely certain knowledge. A certain basis for knowledge. • The only piece of information he found true— • I exist: “I think; therefore I am.”

17. Descartes Clarity • Standard or criteria- clarity and distinctiveness must be the marks of truth, the distinguishing characteristics by which you can tell the true from the false • Descartes like Plato belonged to a group known as Rationalists and would not have discredited scientific theory, since science deals only with the visible world, which can never, accordingly, be known with absolute certainty. • Rationalist deal with “pure ideas” a world that never changes nor does knowledge of it change. • For example: 1 is always 1

18. Empirical Philosophers • Empiricism: attempts to explain knowledge in terms of sense experience. • John Locke—our knowledge comes to us through our senses and we have no innate ideas • Mind as a blank paper and experiences create information to our senses which we reflect upon • Locke’s “Simple Ideas” not compounded with any other element like smell of a rose, cold ice. • Divided our sensations into primary (belonging to the object—size/shape) and secondary (color). Difference between ordinary experience and scientific description

19. Locke on Ideas--David Banach • Ideas are the objects of thought and understanding. Whenever we think, perceive, or contemplate, we think about ideas. • All ideas come from Experience. Hence, all the materials of reason and knowledge arise from experience. None are innate. • Experience may be of two different origins: •  1. Sensation- These are ideas of external sensible objects conveyed to us by the senses: yellow, white, hot, cold. • 2. Reflection- These are perceptions of the internal operations of our minds: thinking, doubting, willing. • 3. Abstraction- separating one property from many particular ideas: all general, abstract ideas. • Complex ideas can also be of three different types of objects: • A. Modes- these don't contain the supposition of independent subsistence. •       1. Simple- combine same type of ideas: number (12). •       2. Mixed- combine different types of ideas: beauty combines color and form. • B. Substances- These represent distinct particular things. •       1. Single- An individual taken to exist by itself: a man. •       2. Collective- a group consisting of other individuals: an army or flock of sheep. • C. Relations- These are relationships between other ideas, substances, or modes.

20. Locke on Ideas • Ideas from these sources may also be of two basic types: • 1. Simple Ideas- Of one uniform appearance or conception in the mind; cannot be created or destroyed. • 2. Complex ideas- Constructed by us in various ways using other simple ideas. • Simple ideas: These can be of four basic types: •                 a. Ideas from one sense: Light, noise, taste, smell, heat, solidity, texture. (secondary properties) •                 b. Ideas from more than one sense: space, extension, figure, rest, motion. (primary properties) •                 c. Ideas from reflection only: perception, willing. •                 d. Ideas from both sense and reflection: pleasure and pain, power, existence, unity. • Complex Ideas: These are constructed by us using three different methods: • 1. Combination- putting various ideas together into one complex idea: a unicorn constructed from the ideas of horn and horse. • 2. Relation- seeing the relation between ideas: equality. • 3. Abstraction- separating one property from many particular ideas: all general, abstract ideas. • Complex ideas can also be of three different types of objects: • A. Modes- these don't contain the supposition of independent subsistence. •       1. Simple- combine same type of ideas: number (12). •       2. Mixed- combine different types of ideas: beauty combines color and form. • B. Substances- These represent distinct particular things. •       1. Single- An individual taken to exist by itself: a man. •       2. Collective- a group consisting of other individuals: an army or flock of sheep. • C. Relations- These are relationships between other ideas, substances, or modes.

21. Locke on Ideas • Simple ideas: These can be of four basic types: •                 a. Ideas from one sense: Light, noise, taste, smell, heat, solidity, texture. (secondary properties) •                 b. Ideas from more than one sense: space, extension, figure, rest, motion. (primary properties) •                 c. Ideas from reflection only: perception, willing. •                 d. Ideas from both sense and reflection: pleasure and pain, power, existence, unity. • Complex Ideas: These are constructed by us using three different methods: • 1. Combination- putting various ideas together into one complex idea: a unicorn constructed from the ideas of horn and horse. • 2. Relation- seeing the relation between ideas: equality. • 3. Abstraction- separating one property from many particular ideas: all general, abstract ideas. • Complex ideas can also be of three different types of objects: • A. Modes- these don't contain the supposition of independent subsistence. •       1. Simple- combine same type of ideas: number (12). •       2. Mixed- combine different types of ideas: beauty combines color and form. • B. Substances- These represent distinct particular things. •       1. Single- An individual taken to exist by itself: a man. •       2. Collective- a group consisting of other individuals: an army or flock of sheep. • C. Relations- These are relationships between other ideas, substances, or modes.

22. Locke’s Kinds of Knowledge • 1. Inspection of two or more ideas to see if they are identical or different • 2. Intuitive Knowledge—when simply looking at two or more ideas, we see immediately that something is true about them. • 3. Demonstration—connect ideas together to see if they have something in common—compare them with some others • 4. Sensitive Knowledge—experience • 5. Limitations of Knowledge—to the respects in which various ideas of ours agree or disagree • 6. External Reality—reality of things—real knowledge

23. Bishop George Berkeley • Does Matter Exist? • What constitutes reality? • Sensations (taste, heat, etc.) • He concludes sentient beings(capable of feeling) experiences consist of sensations • Therefore, material objects cannot “know” • In other words, things only exist as a referent on in and of themselves.—The existence of things consist of them being perceived. • IMMATERIALISM—all that we can perceive is an idea. Ideas can belong only to minds and cannot have an existence independent of minds. If I am not responsible for my wishes, the ideas must have some kind of existence apart from my mind. But ieas can belong only to some mind. Then there must be some other mind that possesses, controls, all my ideas at will—Berkeley claimed a universal mind or God

24. Limerick for Berkeley's Thesis • There was a young man who said, “God, • I find it exceedingly odd • That this tree I see should • Continue to be • When there’s no one about in the Quad.” • Reply • “Dear Sir: • Your astonishment’s odd: • I am always about in the Quad • And that’s why the tree • Will continue to be • Since observed by • Yours faithfully.--God

25. David Hume • Science of Man • Impressions and ideas (degree of force and liveliness) • Simple and complex (simple ideas are just our simple impressions and that impression have always occurred first.) • Memory and Imagination (patterns) • Memory—a fixed order or sequence • Imagination—arrange ideas in any order we like • Causation—knowledge consists of information that can be gained from the inspection of two or more ideas (intuitive and certain)

26. Logic • Logic is the branch of philosophy that reflects upon the nature of thinking itself. • Whether this thinking is correct or not • Deductive vs. Inductive logic • Premise: All Europeans are mortal. • DEDUCTIVE: (a) All Europeans are human beings and (b) all human beings are mortal. If both sentences are true then then it is impossible for the premise to be false • INDUCTIVE: One may not believe the sentence that all human beings are mortals, so one might prefer a different procedure. From the particular to the general • (a) Every European born before 1830 has died. (b) Europeans are still dying. The truth of (a) and (b) makes it probable that All Europeans are mortal is true. However unlike deductive argument above the truth of these reasons does not make it certain that all Europeans are mortals. It is still possible that (a) and (b) may other be true and yet that someone alive today or who may be born in the future will be immortal. Inductive is based on inferences that are probable given the evidence of certain propositions.

27. Fallacies • Any sort of mistake in reasoning or inference; it is a term used to denote anything that causes an argument to go wrong • Ambiguity—if a term has more than one meaning. We do not understand the meaning of the sentence • Grammatical misuses—The Newport Beach was far ahead of the others when she crossed the finish line. Her nose up in the air, salt water pouring across her bows, Mrs. Williams guided her skillfully to the cheering crowd. • Contextual Fallacies • Fallacy of significance—”62% of those doctors who smoke, some Raspies!” This is misleading, since it does not say how many doctors do not smoke, nor does it say that they smoke only Raspies. • Emphasis—incorrect emphasis of words in a sentence. “Protection Guaranteed against Everything except death, injury, disease.” • Out of context—I would enjoy this book if, and only if, it were the only book in the word, or if I were on a desert island and had nothing else to read. “I would enjoy this book…if I were on a desert island.” • Arguing from Authority—”They say…” Or Ms Cotner’s says…. One cannot prove the truth or falsity of a statement merely because someone of authority says so. • Sentiments—reporting how people feel about it. “The world is flat.” “But everybody believes that.” Appeal to sentiment. • Ignorance—statement must be true because there is no evidence to disprove it We could prove dragons, elves exist because there is nothing that disproves them • Begging the question—circular arguments • A. Moses is divinely inspired • B. How do you know? • A. Because the Bible says he is • B. But how do you know the Bible is reliable? • A. Because it was written by Moses, who is divine.

28. More Fallacies • Composition—what is assumed to be true of a part is asserted to be true of the whole.-- John O’Brien is an Irishman and belligerent; therefore, Ireland is belligerent. • Division—true of the whole must be true of its parts—The US is a wealthy country; therefore, Ms Cotner is wealthy. • Irrelevant conclusion—starting out to prove something but proves something else. • Statistical—Schnook detergent washes 91 times cleaner than any other soap. What tests? How does one define “cleaner than?”

29. Gardner’s Theory of MI • Gardner's theory argues that intelligence, particularly as it is traditionally defined, does not sufficiently encompass the wide variety of abilities humans display. • In his conception, a child who masters multiplication easily is not necessarily more intelligent overall than a child who struggles to do so. The second child may be stronger in another kind of intelligence, and therefore may best learn the given material through a different approach, may excel in a field outside of mathematics, or may even be looking through the multiplication learning process at a fundamentally deeper level that hides a potentially higher mathematical intelligence than in the one who memorizes the concept easily. "The theory suggests that, rather than relying on a uniform curriculum, schools should offer "individual-centered education", with curriculum tailored to the needs of each child." • Multiple Intelligences: Visual/Spatial, Bodily/Kinesthetic, Mathematical/logical, Interpersonal, Intrapersonal, Musical, Verbal/linguistic, Naturalistic,

30. So Now • What do you think? • Explore • Research • Define • Determine • WRITE YOUR LOGIC