4/9/13 CAS plan is due 4/23/13 or earlier; talk to Ms. Gant if you have questions. Quarter 4 TOK Reminders: – Work is due in class on due date – You need to be taking notes from the text – You may not print out the powerpoints I give and use as notes on the quizzes. – Participation will be a weekly grade in this class this quarter. – If you need something printed, please arrive early to get it done. If you send me something via , I will print it when you get here, so build time in for this.

And finally… You asked IB teachers not to grade every little thing and to give you more time for big assignments— there is reciprocity in that request that falls on you: Teachers grade every little thing because they fear you won’t do it unless there are points attached; in other words, you won’t do something if you won’t be turning it in. Teachers have to be able to trust that you’ll do something even if you’re not graded traditionally on it. When given 2-3 weeks for bigger assignments, quality needs to reflect that.

Reason and Logic I think, therefore I am. -Rene Descartes

A few more vocab words A priori Post priori Antecedent Consequent Explicit Implicit Axiom erroneous Microcosm Anomaly Aberration Incontrovertible Dogma Doctrine Verites de fait Verites de raison

My dear, Watson… The curious incident of the dog in the nighttime…. The guard dog will bark at strangers. The guard dog did not bark. The murderer was not a stranger. “It’s elementary!”

Tied to other WAYs of knowing: Remember that we develop reason and logic based on a system of rewards that appeals to sensory/emotion/language. Think of a baby learning what things are called…what rewards does he get when he is correct?

Logic is the art of reason. Three kinds of Reasoning: Deductive Inductive Creative/informal Rationalism: argues that reason is the most important source of knowledge; rationalists are suspicious of knowledge based in perception or emotion.

Logical assumptions: premises, drawing conclusions independent of external factors like culture, class, etc. Reason helps us develop consistent beliefs about the world. However, is it always appropriate? Does it leave room for faith/belief?

Reason is said not to be the way to get closest to truth but rather the best way to preserve the truth.

Bad reasoning… Fallacies: invalid forms and patterns of reasoning (more on this later). Rationalization: manufacturing reasons to justify invalid arguments, positions, or prejudices. Causes of bad reasoning: ignorance, laziness, pride, prejudice…can you think of others?

Implications Implication: logical relation between two ideas. Most basic: If A, then B. A implies that B will occur. If idea A is true, idea B cannot be false.

Laws of thought Five Laws of Thought: 1. Law of Identity: If A, then A. If this is a pencil, then it is a pencil.

Law #2 Law of non-contradiction: Nothing can be A and not A. This pencil cannot also not be a pencil.

Law #3 Law of Excluded Middle Everything is either A or not A. Everything is either a pencil or not a pencil.

Law #4 All proof must end somewhere, and is dependent on developed systems of classification. The word for this object is ‘pencil’. Therefore it is a pencil.

Law #5 The Law of Infinite Regress A.Infinite regress arises when we ask what are the justifications for the reasons themselves. B.If the reasons count as knowledge, they must themselves be justified with reasons for the reasons, and so on, ad infinitum. This is a pencil. Why? Because it writes on paper with lead. But why does that define it as a pencil? Because all of these other objects that also write with lead on paper are called pencils. Why?

“Reliable” generalizations Generally reliable…generalizations…will have the following: Number of confirmed experiences are greater than 1. Variety of circumstances with same results. Exceptions and counter examples have been examined. Coherence—even more evidence required for surprising claims or results. Subject area reliability (For more, see pg. 123 of text)

Truth and validity Truth and validity are NOT the same thing. Often, premises are based on generalizations. TESTS: – Are the premises true? – Are the arguments valid? AN argument that follows a valid process may not be true.

Reason= – When the first two premises are true, the conclusion will be true. – When one of the two premises is false, the conclusion is false. – If the conclusion of an argument is not true, then either the argument is invalid or at least one premise is false.

Example of a syllogism that is ALWAYS valid: – All As are Bs, Some As are Cs. Therefore, some Bs are Cs. – Can you draw this in a Venn diagram? For more, see pg of text.