Philosophy Sept 28th Objective Opener 10 minutes Analyze Plato’s Allegory of the Cave by answering questions and participating in a group discussion. Finish your maps of the school. Be sure to label it with the kind of map Population Resources Subject Cliques other

Section 7.1 Things Aren’t Always What They Seem Skepticism about Skepticism

Heraclitus Everything is in flux--the world is being created anew each instant. “You cannot step into the same river twice, for the water into which you first stepped has flowed on.”

Parmenides Only that which is unchanging is real. Nonexistence (nothingness) cannot exist. From nothing, nothing comes. So reality must be composed of an eternal, unchanging substance.

Exercise: Try to think about nothing for 2 minutes

Thought Probe: Thinking about Nothing Paramenides believed that because nonexistence cannot exist, it cannot be thought about. Do you agree? Can you think about nothing? That is, can nothingness be the object of your thought? If so, can you describe what you’re thinking about when you’re thinking about nothing?

Plato’s Allegory of the Cavehttps://www. youtube. com/watch Handout

Small group discussions –choose a recorder to write down the group’s responses and assign the rest a question to report back to class when class comes back together. Would you want to be released from the cave? Why or why not? What is like the cave in our world? How is the way you understand the world, your ideas and beliefs, shaped by the actions of others? Who has the power to shape your ideas and beliefs? In what ways is this good and in what ways is it not so good? Are there things you know to be true? What are they, and how do you know them?

Crash Course Philosophy: Descartes https://www.youtube.com/watch?v=MLKrmw906TM

Cartesian Skepticism Sense experience can’t give us knowledge because knowledge requires certainty and nothing we learn through our senses is certain. We can know something only if we are certain that it is true.

Thought Experiment: Descartes’s Dream How often has it happened that you thought something was real only to find out that you were dreaming? Can you know for certain that you’re not dreaming right now?

Descartes’s Dream Argument We can’t be certain that we’re not dreaming. If we can’t be certain that we’re not dreaming, we can’t be certain that what we sense is real. If we can’t be certain that what we sense is real, we can’t acquire knowledge through sense experience. Therefore, we can’t acquire knowledge through sense experience.

Thought Experiment: Descartes’s Evil Genius (Unger’s Mad Scientist) Suppose that an evil genius used telepathy (or a mad scientist used electrodes) to put false ideas into your mind. Can you be certain that you’re not under the influence of such a person right now? If not, can you have knowledge of the external world?

The Evil Genius Argument We can’t be certain that our sense experience is not caused by an evil genius. If we can’t be certain that our sense experience is not caused by an evil genius, we can’t be certain that what we sense is real. If we can’t be certain that what we sense is real, we can’t acquire knowledge through sense experience. Therefore, we can’t acquire knowledge through sense experience.

Cartesian Certainty Descartes cannot doubt that he is thinking, for doubting is a type of thinking. And Descartes can’t doubt anything unless he exists. So Descartes claims that he can be absolutely certain of one thing, namely, “I think, therefore I am.”

What Descartes Knows Descartes knows the contents of his mind; if he seems to see a tree, he knows that he seems to see a tree. To acquire knowledge of the external world, he needs a principle to bridge the gap between appearance and reality.

The Principle of Clarity and Distinctness God exists and is no deceiver. If God exists and is no deceiver, then whatever I clearly and distinctly perceive is true. Therefore, whatever I clearly and distinctly perceive is true.

Application of the Principle of Clarity and Distinctness I clearly and distinctly seem to see a tree in front of me. Whatever I clearly and distinctly perceive is true. Therefore, there is a tree in front of me.

The Cartesian Circle Descartes can’t know that God exists and is no deceiver unless he knows that what he clearly and distinctly perceives is true. But he can’t know that what he clearly and distinctly perceives is true unless he knows that God exists and is no deceiver.

Shadow of a Doubt vs. Reasonable Doubt To know a proposition, it doesn’t have to be established beyond a shadow of a doubt. It only has to be established beyond a reasonable doubt. This is the standard used by courts to adjudicate matters of life and death; it can also be used to adjudicate matters of knowledge and ignorance.

The Problem of Induction Induction assumes that the future will resemble the past. That belief can’t be justified a-posteriori because all a- posteriori reasoning assumes its truth. That belief can’t be justified a-priori because its falsity doesn’t imply a contradiction. So it looks like that belief can’t be justified.

Thought Probe: Science and Faith We can’t prove that the future will resemble the past (that like causes produce like effects). Yet all scientific inferences are based on that belief. Is science, then, based on faith? Is science a form of religion?

The Kantian Synthesis According to Kant, the mind is an information processor. It takes raw sense experience and brings it under certain concepts (like causality).

Thought Probe: Constructing Reality Are scientific laws invented or discovered? The traditional view: scientific laws exist “out there” in the world and science discovers them. Kant’s view: “The order and regularity of the appearance we entitle nature, we ourselves introduce.” For Kant, reality is a human construct. Which view do you think is correct? Why?