Philosophy
“Philosophy has lost all her children”
Physics
Biology
Psychology
Political Science
Economics
Social Sciences
Justice and Law
Logic
Aesthetics
Analysis of the experience of the beautiful or of art.
Metaphysics (Being)
Coined accidentally because it came “after the physics” in Aristotle’s writings.
Many philosophers have abandoned metaphysics in favor of epistemology, which is the theory of knowledge.
Metaphysics is concerned with principles, structures and meanings that underlie all observable reality
Ontology, the major branch of metaphysics, examines the nature of being and existence.
Cosmology examines origins of universe and the order of things.
Theology is usually included as a part of metaphysics.
Substance(s)
Monism
All things are made of a single substance
Materialism:” there are atoms in the void”. In monistic materialism everything is reduced to particles in motion,which sometimes collide.
Idealism: There are only ideas, or only minds and ideas, no matter or anything external to the mind.
Neutral Monism (matter and ideas are manifestations of a third, common substance which is not reducible to an idea nor matter.)
Pluralism (Dualism)
More than one irreducible substance exists. (e.g. Dualism, which assumes two substances: mind, and matter; or: spirit and matter)
Problem with dualism: If these substances are irreducible how do they affect one another, i.e. how do they interact?
Earth, air, fire (i.e. change), water, atoms & void and the Logos. One of the earliest recorded uses of the word Logos is in the works of the Greek philosopher Heraclitus about 600 B.C. Our word “logic” is derived from the Greek word Logos. Heraclitus used the word Logos to refer to the rational principle of order in the universe. Webster’s New World Dictionary defines Logos as “Reason, thought of as constituting the controlling principle of the universe and as being manifested by speech.” The Logos is still thought of as a substance. In the Gospel According to John the author begins the book with “In the beginning was the Logos, and the Logos was with God, and the Logos was God”. The Gospel According to John in the King James Authorized Versionof the Holy Bibletranslates “Logos” as “the Word”. This is, in part, what led me to have such a great respect for language and logic. Since I have learned a bit more about logic I have gained an appreciation of the beauty and especially the power of logic, language, reason and rationality.
Universals vs. Particulars
Realism: relations (<, >, :: ), concepts, and laws of nature have objective existence.
Nominalism:relations, concepts and laws of nature exist only in our brains or only in our minds and have no objective existence.
Cause and effect: how can we be sure such a relation has objective existence and really holds?
Is there a necessary connection between causes and effects, or are perceived cause-effect relations accidental? Might a law of cause and effect someday fail or even be reversed?
Determinism – Theory assuming every event is the result of antecedent causes.
Indeterminism – Theory assuming some or all events are not caused.
Free-will – in particular, human acts or decisions are not caused.
In either case, determinism or indeterminism, there seems to be a problem with holding an agent responsible for their acts.
Responsibility under determinism – How can we justify punishing or rewarding, e.g. criminals if they had no choice, as in the case of determinism where their actions were caused and they could not have done otherwise?
Responsibility under indeterminism– If free-will holds, then the cause-effect relation does not hold in the case of human acts, so rewards and punishments won’t change behavior. In this case human acts are not caused, so they are random; so,does it make sense to hold people responsible for their acts when there is nothing we can do that will change them or their behavior in the way we want?
Functionalist theories of consciousness (and reality)
Computational theory of mind
Mind : body :: software : hardware
Epistemology (Knowledge – justified, true belief)
Deals with problem of skepticism
Pure skepticism seems to me to be untenable. You must believe something in order to make decisions, for instance you must believe that the air around you is not poisoned in order to decide to take your next breath. However, every rational decision we make is determined by our beliefs, so it seems to be a good idea to test what you believe so you can be relatively sure that it is true. For this reason it seems to me that doubt can be a useful tool.
Criteria of belief
Apriori(before sense experience) (rationalism)
Before sensory experience
Rational thought, logically understood without regard to, and possibly before sensing or experiencing the world outside our self.
Innate ideas
Certain general propositions (called necessary or apriori) are known truths in the absence of sense data.
An example would be truths of deductive logic, like: if all men are mortal and Socrates is a man, then Socrates is mortal. Rules of arithmetic and geometry (and perhaps all mathematics) are apriori.
A posteriori(after sense experience) (empiricism)
After sense experience
Knowledge comes from sense experience
Tabula rasa (blank slate, we are born with no knowledge, no mental structure. We learn everything we know from our experiences as the world impinges upon us through our senses.
Consider the problem of the criterion of truth.
Vicious circle: if we use some criterion to test the truth of a belief,then how do we know that our criterion is true? What criteria do we use to test our criteria?
Science seems to use the combination of the two to determine what is true.
Theories can be tested for validity a priori.
Experiments can be done to determine if current theory matches the results our sense experience presents to us.
Deduction vs. Induction
Deductive logic
Start from premises, which are statements previously proven true or else assumed to be true.
Use rules of inference to argue from premises to the conclusion.
The conclusion of a valid argument is necessarily true if the premises are true.
We say the conclusions of a deductive argument hold the premises “hostage”.
We also say that a deductive argument makes explicit what was implicit in the premises.
Deductive logic moves from the general to the specific
Inductive logic
Inductive logic is reasoning from the specific to the general. An example is the following: because there are so many specific instances demonstrating that the Sun rises in the East about every 24 hours, we inductively generalize to the statement that the Sun will continue to rise in the East about every 24 hours.
The conclusions arrived at inductively are not guaranteed to be true; the conclusions arrived at deductively are. The conclusions arrived at inductively are said to be more or less probable.
Subjectivism vs. Objectivism
That which is objective can exist even though no one perceives it and even though it is not in anyone’s consciousness.
The existence of that which is subjective depends on a subject which is perceiving or is conscious of the object or event.
Ethics – Practical philosophy (Good life or Good decisions)
What is happiness?
What is a good life?
Sometimes it is phrased as “what is right?”
Compares & contrasts moral systems
Goal is good acts, based on good decisions or choices.
Deontologicalvs.Teleological
Deontological (Moral Realism – objective standards or principles of value or goodness exist.)
Absolutist
Do what rules say to do without regard for consequences.
Categorical imperative: “Act on maxims which can at the same time have for their object themselves as universal laws of nature” - Immanuel Kant
Authority’s prescription of rules to follow
Teleological - based on consequences.
Must evaluate outcome of decisions
Benefit/Cost Analysis
Subtract the value of the costs of the outcome of a decision from the value of the benefits of the outcome of a decision to arrive at the value of the outcome of the decision
If the result of the benefit/cost analysis is positive, we might say there is some profit in acting on this decision, or that there is some positive value associated with the outcome of acts based on this decision.
Opportunity Cost
This is the value of the best foregone decision.
Assumes resources are limited or scarce.
Given a finite amount of resources, what is the best way to invest those resources? What decision(s) should be made with respect to the allocation of the scarce resources? This is a question posed in economics, but might also serve us well here in ethics.
There are mathematical algorithms which give the optimum choice or allocation of resources. These algorithms require that you set them up with the resource constraints
The above algorithms can be incorporated into a computer program, for instance in Decision Support Software, to help people make decisions.
Evaluation entails axiology – theory of value. What is the criterion we use to evaluate or to decide what is true?
Hedonism: maximize pleasure or minimize pain for the individual
Utilitarianism
Maximize pleasure or minimize pain for the greatest number. “The greatest good for the greatest number”.
Rawlsian criterion of economic justice: the worst off must be made better off than they were before the decision was acted upon.
In economics, we often let a market function set values.
In a formal language or theory our axioms or basic beliefs determine all the conclusions of the theory, and so are of supreme value with respect to what we believe is true or false.
Some of my students have suggested that what is true is a personal matter and that truth may be different for each person, but how can we live together without agreements, especially without agreements about what is true and what is false?
Theory of Obligation
Should vs. Ought
Duty (to community, self, etc.)
Morals are often normative, approbative, prescriptive
Faculties affecting decisions
Intellect
Appetites
Affections
Emotions
Reason
Will
Periods
Ancient
Thales: attempted an explanation of the world that does not depend on gods or mythology
Medieval period, also known as the dark ages
Dominated by church in Europe
Focused on Aristotle’s theories as interpreted by St. Thomas Aquinas
Remainder of ancient philosophy science and mathematics were preserved by Islamic philosophers
Math, Science, Platonism, Pre-Socratics
Ancient philosophers knew world is round, atomic theory, biology, math, algebra, geometry, etc.
Modern
Breaking free of church restrictions
Free thinkers
Renaissance, humanism, enlightenment
Logic
Sometimes known as a formal system or a formal calculus.
Method used in philosophy to formally classify arguments as good or bad, valid or invalid.
Logic is formal and can represent or symbolize any other system that has the same form.
Example: Formal equivalence of thermodynamics and information theory
Thermodynamics
The physical theory describing order and disorder and transformations of power from heat into work and vice-versa,
Information theory
The theory concerned with the encoding, decoding, storage and retrieval of information and with the transmission of a message through a given channelwith a given degree of accuracy.
Both theories involve a collection of formulas used to explain, predict and control the subject phenomena.
It turns out that the formulas of thermodynamics are equivalent to the formulas of information theory, so one theory is formally equivalent to the other.
This suggests that information and energy (power) are formally equivalent, because that is what these two formally equivalent theories describe. This gives new meaning to the phrase “knowledge is power”.
We probably could not have discovered this equivalence without the tool we call logic.
Meta-logic: system we use to talk about a logical system. It is a “bigger” system containing the logical system we want to study. It is bigger because we need extra symbols or letters in the alphabet of the meta-system in order to be able to refer to the system we are studying in an unambiguous way.
A logical system with an interpretation is a language
Interpretation: Assignment of meaning or significance to the symbols of a formal system so that the wff have a meaning or refer to entities other than themselves and the wff can have a truth value (true or false) assigned to them.
Syntax: the rules of the grammar of a language
Production rules are recursive replacement rules which determine the set of productions, starting with the axioms of the system and generating from them, via the production rules or rules of inference, the sentences that properly belong to the language. Formal syntax makes no reference to the meaning of the symbols or to the sense of the expressions of the language
Given a theorem or string of symbols from the alphabet of the system, the string can be “parsed” using the grammatical rules of the language to” recognize” the string, i.e. to determine if the string is a proper member of the language.
Semantics: the meaning associated with the formulas of a formal system.
Consistency of a system is necessary
Contradictions
If a statement can be both true and false in the same language or logical system, that is a contradiction
If a system contains a contradiction, it is inconsistent.
This is undesirable, because from a contradiction absolutely any statement can be proved to be true without any restrictions on the meaning of the statement.
Axiomatic method
Axioms are statements we assume to be true, or self evident.
Different sets of axioms determine different theories.
Example: Euclidean geometry vs. hyperbolic or spherical geometry. We use the rules of logic (rules of inference) in all three types of geometry, but we start with slightly different sets of axioms for each system.
Originally geometry meant the study of the Earth or the study of land or the studies of the properties of space. Geometry was used to survey real estate property boundaries after the yearly flooding of the Nile in ancient Egypt, and for other types of engineering. The pyramids were almost certainly built using geometry to help design them before expending resources to cut, transport and lift the heavy stones into place.
In Euclidean geometry, which is done in a 2-Dimensional plane, depends on an axiom called the parallel postulate. If you are given a line and a point not on that line, there is a unique line through the given point that is parallel to (i.e. does not intersect) the given line.
Spherical geometry: In contrast to Euclidean geometry, which is done in the plane (a flat space) spherical geometry is done on the surface of a sphere. Think of a globe of the Earth with lines of latitude and longitude. Only great circles are considered to be straight lines on a sphere. A great circle is a circle that goes around the surface of the globe and is such that the center of the circle is the same point as the center of the sphere. On a globe, lines of latitude other than the equator are not great circles and so would not be considered to be straight lines because they don’t trace out the shortest path between two points on the surface of the sphere. There are no parallel lines in spherical geometry because any two great circles on a sphere must intersect.
In hyperbolic geometry, which is done on a surface called a hyperbolic paraboloid (which is, roughly speaking, a saddle-shaped surface), there are an infinite number of lines through a point that are parallel to the given line. This is in contrast to Euclidean geometry, which assumes only one parallel line, and spherical geometry, which assumes no parallel lines.
So, the above shows that by including the parallel postulate (or axiom) in his geometry, Euclid came up with only one type of geometry; when really there are many possible geometric systems. Which geometry you end up with depends on your selection of axioms, like the parallel postulate.
Which geometry best represents nature? It turns out that space is not flat, as it is in Euclidean geometry; space is curved in the vicinity of strong gravitational fields. Current theory indicates that a non-Euclidean geometry most accurately represents the natural world we live in. This is counter-intuitive. We usually think of space as flat; i.e. that straight lines don’t curve. Mathematics and logic, together with the results of experiments show that our intuition is wrong. While Euclidean geometry is adequate for measurement locally, if you are measuring a larger area where the Earth’s curvature affects the measurements, it is more accurate to use spherical geometry. When measuring on cosmic scales, It seems hyperbolic geometry is may be the better choice of systems. This is mind-boggling. How can empty space be curved? It is counter intuitive.
Example: N-dimensional Cartesian spaces or vector spaces
We have been talking about two-dimensional geometries so far, but geometry can be done in higher dimensions.
A dimension describes a degree of freedom. It also describes how many numbers are necessary to uniquely specify a point in the space. If you describe a collection of points, you can describe an object in the space, or the motion of an object in space. We can describe the relations between objects with a mathematical function in this space. This allows us to model space, objects and processes with a language.