Philosophy, Logic and Human Existence.pptx

GTS211:
PHILOSOPHY, LOGIC @HUMAN
EXISTENCE
OBJECTIVES OF THE COURSE:
Philosophy teaches us to be Critical
Philosophy also teaches us to be Rational.
Philosophy is capable of inculcating Morality in us.
Philosophy also teaches us Responsibility.

WHAT IS PHILOSOPHY?
• Philosophy as a course or discipline is difficult to define.
Philosophers do not agree among themselves as to how
their discipline should be defined. Fasoro opines that if
philosophy has other names, it should be ‘controversy.’
C. D. Broad argues that the only way to define
philosophy is to look at what the people that are called
philosophers do on daily basis. Some people, especially,
non-philosophers see philosophy simply as Principle.
Philosophy is more than that

DEFINATIONAL PROBLEM
•But why is the course difficult to define? Olusegun Oladipo says:
• The intellectual endeavor called philosophy is not easy to define. This is
because, it is difficult to identify the subject matter of philosophy the way
we can specify the concerns of economics, sociology, biology and political
science, for example. Also, we cannot pinpoint a method as the
philosophical method the way we can talk of scientific method, for
instance, consequently, the nature of philosophy is always a subject of
debate among philosophers.

ENTYMOLOGICAL MEANING
•It is generally accepted by all philosophers that
Philosophy has its origin in two Greek words. Philo
which means Love and Sophia which means
wisdom or knowledge. Philosophy therefore,
etymologically, means “love of wisdom” and
philosophers are labelled as lovers of wisdom.
Wisdom or knowledge as used by them is the same
as reality. Those who seek to know the reality are
philosophers.

STANILAND’S DEFINITION OF PHILOSOPHY
•The definition offered by H. S. Staniland is
this: “Philosophy is the criticism of ideas we
live by.” The purpose of criticism, according
to her, is not to reject the idea but to
evaluate it. This definition is accepted by
many philosophers and students of
philosophy including this course teacher. That
is while he sees philosophy as the rejection of
both dogmatism and extremism

BRANCHES OF PHILOSOPHY
•There are four core branches of philosophy:
epistemology, logic, metaphysics and ethics which
some prefer to call axiology. Besides, there are other
minor branches such as philosophy of education,
philosophy of religion, philosophy of law, philosophy
of science, philosophy of social science, social and
political philosophy, philosophy of history, history of
philosophy and so forth. Our concern in this course is
limited to the core branches.

EPISTEMOLOGY
•Epistemology is coined from the Greek word
‘episteme’ which means knowledge. It is the
branch of philosophy that studies knowledge and
knowledge claims. It deals with the meaning of
knowledge, how knowledge is different from
opinion, the limitations to human knowledge and
the relation between the object of knowledge and
the subject of knowledge. Can we know, and if
we can, then, how can we know? When we claim
to know, what are we saying or what do we
mean?

TRADITIONAL CONCEPTION OF KNOWLEDGE
•The belief was that knowledge is possible and
we actually know. Traditionally, knowledge, as
we find it in one of Plato’s books, Theaetetus,
knowledge was defined as justified true belief.
That is for one to know, three conditions must
be satisfied: he must believe in what he claims
to know. What he knows must be true, and he
must have justification or reasons to back up
his knowledge claim.

TRADITIONAL CONCEPTION OF
KNOWLEDGE CONT
•. For instance, if one claims to know that Bishop
David Oyedepo is the Chancellor of Landmark
University, Omu-Aran, it must be true that Bishop
Oyedepo but not Professor Ajanaku is the chancellor
of the university. The person must also believe that
Bishop Oyedepo is the Chancellor because it will
amount to a contradiction for one to say that he
knows but he does not believe what he claims to
know. Lastly, he must have reasons to back up his
belief that Bishop Oyedepo is the Chancellor

THE SOPHISTS AND KNOWLEDGE
•Sophists in the ancient time were itinerant teachers.
They moved from one place to another teaching
people and had students. They collected money for
the services they rendered. But, for them, there is no
knowledge and nobody can know. The reason is that,
for one to know, what he claims to know must be
certain. Given this condition, they believed that since
nothing is certain, because, everything is changing,
knowledge is impossible

THE SOPHISTS AND KNOWLEDGE
CONT
•The two most popular among the sophists are
Gorgias and Protagoras. According to Protagoras:
“Man is the measure of all things.” That is, what
is true to you is true to you and what is true to
me is true to me. So, no one is right and
everyone is wrong. For Gorgias: Nothing exists.
If anything exists, it cannot be known. If it can
be known, it cannot be communicated, because
of the problem of other minds.

REFUTATION OF THE SOPHISTS’ POSITION
•The sophists went about teaching people and collecting
money. Those they taught at least, believed that their
teachers knew more than them. Now, if the sophists are
teacher, what were they teaching if there is no
knowledge? Also, the man who claims that there is no
knowledge or that nothing can be known, at least,
knows something. He knows that nothing can be
known. The fact that he knows that nothing can be
known is knowledge on its part.

RATIONALISM AND EMPIRICISM
•The challenge by the sophists that nothing can be
known or that knowledge is not possible drove
philosophers into serious thinking. They came up
with the same position that knowledge is
possible, and that, we in fact know. They however
disagree on how we know, that, the sources of
knowledge. They fall into two opposing camps,
rationalism and empiricism.

THE RATIONALISTS
•The rationalists hold that knowledge is possible and that
we know. According to them, we know by reason. That
is our major or only source of knowledge is reason.
Plato is the known founder of this tradition or school of
thought. According to him, there are two worlds; world
of reality or forms and the world of appearances or the
sensible world. The soul formerly existed in the world of
Forms before it migrated into this physical world. Things
in the world are real but those things in this world are
mere appearances.

THE RATIONALISTS CONT
•The soul of man once lived in the world of
Forms but because of pains at birth, it forgot
everything it used to know. On getting to the
age of reasoning, and with the aid of
teachers, he is able to recognize those things
it used to know when he comes across them.
For Plato therefore, knowledge is by
Recollection.

• Rene Descartes is another rationalist. In his book, Meditation,
Descartes subjected everything he had known to doubt. He
doubted simple knowledge of mathematical truth, 2+2=4.
He said that it was possible for an Evil genus to deceive him
that 2+2= 4 instead of 5. He also said that he once dreamt
that he was sitting by fire-side, with a paper in his hand.
Later, he woke and found out that he had been dreaming.
But, according to him, in his methodic doubt, it was possible
that when he thought he was awake, that that may even be
a continuation of his dream. So, there was no way of
distinguishing between dreaming life and awake.

•Amazingly, Descartes said that whether he
was awake or no, or whether an evil
genus was deceiving him or not, he was
certain about one thing. He was doubting.
But before he could doubt, he must exist.
He concluded by saying that: “Cogito ergo
sum” meaning, I doubt, therefore, I exist.

THE EMPIRICISTS
•The basic tenet of this school of
thought is that we know by
Experience. That is human beings are
not born with any idea. It is through
our sense organs: sight, hearing,
smelling, touching and tasting that
we know what we know.

THE EMPIRICISTS CONT
•Aristotle is regarded as the pioneer of
this school. According to him “To say
of what is is that is is, and of what is
not that is not is true and to say of
what is not that is is, and of what is is
that is not, is false.

•In the modern time, John Locke is the
most popular empiricist. He argues that
human beings at birth are like idiot.
They know nothing. Human minds are
like Tabula rasa, that is, a clean slate
upon which nothing was written.
Humans therefore know by experience.

•George Berkley on his own argues that esse
est percipii, that is to be is to be perceived.
Without experience, there is no knowing.
However, when humans are not perceiving,
the Universal Mind (God) is doing the
perception. For him therefore, there are no
concrete objects but everything is an idea in
the mind of God.

•For David Hume, there can be
no idea without impression.
He argues that there is no way
a man can know that sugar is
sweet if he had never tasted it.

CONCLUSION ON RATIONALISM AND EMPIRICISM
•Which one is true, rationalism or
empiricism? Both have strong and weak
points. They are partially true and
partially false. We cannot know that
2+2= 4 by experience. In the same vein
we cannot that fire burns by reason. We
therefore need the two schools of
thought to improve on our knowledge.

KNOWLEDGE AND BELIEF
• Knowledge and belief are close related epistemic
terms. They are however not the same.
• Belief or opinion may be true or false. But knowledge
must be true.
• Also, to know is to be certain or sure. But certainty is
not a property of a belief.
• Lastly, while belief is subjective, knowledge is
objective.

THE GETTIER PROBLEM
•Until 1963, the traditional conception
of knowledge as justify true belief was
not publicly challenged. Whether it
was satisfactory or not, because there
was no better definition, the world
continued to cope with it

THE GETTIER PROBLEM CONT
•However, a man called Edmund Gettier,
published his 3-page article titled: Is
Justified True Belief Knowledge? In that
article, Gettier argued that a claim may be
true and justifiable and the person may
have a belief in it, yet, it may not amount
to knowledge. He gave two illustrations

•Two applicants, Jones and Smith attended an interview. On
their way, Jones counted ten coins in the presence of Smith.
At the venue, the president said that Jones will have the job.
Based on these facts, Smith submitted that: The man who
will have the job has ten coins in his pocket. But, unknown
to Smith himself, He had ten coins in his pocket and Smith
invariably had the job. The argument of Gettier is that, Smith
statement was a justified true belief but that does not make it
knowledge because the statement was true by accident.

•Again, there are two imaginary friends,
Jones and Smith. They both had a friend,
Charles whom they had not heard about
for years. Smith use to see Jones driving
a Ford car and he had been helped
severally by Jones. Smith then made
three disjunctive statements

•A= Jones owns a Ford car or Charles lives
in Barcelona.
•B= Jones owns a Ford car or Charles lives
in Berlin.
•C= Jones owns a Ford car or Charles lives
in London.

•B is true not because Jones owns a Ford
car (he actually borrows it) but because
Charles lives in Berlin. But this is only as
a result of guess-work. For Gettier
therefore, we cannot equate knowledge
with guess-work, hence, justified true
belief does not amount to knowledge.

•The need and the search for the
Fourth condition of knowledge is
what philosophers since then
tagged The Gettier Problem

THEORIES OF TRUTH
•If truth, as claimed earlier, is a property of
knowledge, then, what is truth? There is a lot
of controversy over its meaning. Attempts to
explain it has led to the development of
many theories. We shall consider briefly,
three of the most important of them-
correspondence, coherent and pragmatic.

THEORIES OF TRUTH CONT
•The correspondence theory holds that a
statement is true if it pictures or mirrors
fact. Fact, on the other hand is a state of
affair. Bertrand Russell and Ludwig
Wittgenstein are known exponents of this
theory. For instance: “The ground is wet” is
true only if there is a corresponding state of
affair. There are problems with this theory.

•Coherent theory, as proposed by Brandt
Blanshard, holds that a statement is true if only
it coheres or agrees with other statements. In
other words, statements are like a system
where nothing works in isolation but
everything works together. The truth of one
statement therefore depends on the truth of
other established true statements.

•Pragmatic theory holds that a true
statement must work or be of value. It
must produce good result and be a solution
to a problem. As held by the likes of John
Dewey and William James, pragmatic
theory holds that a statement is true if
works.

AXIOLOGY (ETHICS)
•This is the branch of philosophy that is
concerned with the study of the morality of
human conducts. It is also known as Moral
Philosophy. Ethics studies those actions that
are considered as good or bad, right or
wrong, moral or immoral, justice or
injustice, fair or unfair. In fact, ethics studies
human actions as they relate with others in
the society.

AXIOLOGY (ETHICS) CONT
•Ethics is broadly divided into two
aspects: normative ethics and meta-
ethics. Meta-ethics is concerned with
the meanings and evaluation of
ethical terms. Ethical terms include:
good, bad, right, wrong, is and ought

AXIOLOGY (ETHICS) CONT
•In meta-ethics, there are some schools that hold different positions on the usage of ethical terms.
•The Emotional
• The prescribe
• The Subjectivity.
•The Objectivity

NORMATIVE ETHICS
•This aspect of ethics is concerned with standards by
which we judge an action to be good and the other
bad, one action moral and the immoral. Why are
some actions accepted as moral and approved and
others rejected and disapproved of in the society?
Why do we condemn some people for their actions
and commend others for their actions? Philosophers
are divided into two camps in answering these
questions. There are the consequentialists and the
deontologists

CONSEQUENTIALISM
•This class in ethics holds that the goodness or badness,
rightness or wrongness, of an action has to do with the
result or consequence, or the intended result or
consequence of the action. Those actions that are
intended to reduce pain or suffering and increase the
happiness of the majority of the recipients of the
actions are said to be good or right. The actions and
policies that will make few people happy but increase
the burden of the majority are bad or wrong. Those
who hold this thought are called consequentialists or
teleologists or utilitarians. Notable among them are:
Jeremy Bentham and J. S. Mill.

DEONTOLOGY
•Philosophers in this camp are called
deontologists. Among them are: Immanuel
Kant, C.D. Broad and Ross. This school holds
that some actions are good or bad, right or
wrong, fair or unfair in themselves. Whether
they produce good or bad results is not
important. It is the action that should be
considered and not the result, actual or
intended.

DEONTOLOGY CONT
•Kant, the founder of this school of thought in the
modern period, presents a template for the
determination of a good action. This is contained
in what he calls Categorical imperative. According
to him, we must act only on those actions we will
like to universalize. In others words anything that
you would not allow or wish others to do is
immoral, bad, wrong, unfair and unjust, hence, it
must be discarded.

DEONTOLOGY CONT
•Ross on his own argues that Reason will
always tell us the right or good thing to
do and also tells us that some actions are
wrong which we must not do. Broad
argues that Intuition is what tells us the
actions that are morally good and the
ones that are morally bad.

METAPHYSICS
•This is one of the most important branches of
philosophy. It is also one of the most
controversial. It is so important to some
philosophers that they rate it number one among
the other branches. For Aristotle, metaphysics is
the First philosophy. It is also the master of
science. Rene Descartes likens metaphysics to a
tree. The root is metaphysics; the trunk is science
while the branches are the other disciplines.

METAPHYSICS CONT
•For the logical positivists however, metaphysics is a useless venture
and anyone who is a metaphysician is idle and unproductive.
• The logical positivists build on the foundation laid by the leading
British empiricist, David Hume. Hume had argued that what is
meaningful is limited to matter fact and since metaphysical
statements do not belong to belong to this class, it is not
meaningful. Therefore, A. J. Ayer says, any volume or work that
belongs to metaphysics should be committed to flame because, it
can only belong to illusion and sophistry.

METAPHYSICS CONT
The positivists argue that the test for
any meaningful statement is
verification. Metaphysical and
ethical statements are not open to
verification, and so, they are
insignificant and meaningless.

WHAT IS METAPHYSICS?
•Metaphysics is the branch of
philosophy that deals with the
study of what is beyond experience
or the sensible world. It can also be
defined as the study of reality.
Aristotle says it is the study of being
qua being, that is, being as it is.

WHAT IS METAPHYSICS ?CONT
•Metaphysics, also from the Greek word “meta-ta-
physica” is the branch of philosophy that deals with
the study of the nature of reality. According to
Arthur Schopenhauer: “Metaphysics is the
knowledge that goes beyond the possible experience
and nature which renders nature possible.”
Fadahunsi writes that: “Metaphysics is a systematic
study of the fundamental problems related to the
ultimate nature of reality and human knowledge.”

WHAT IS METAPHYSICS ?CONT
• Metaphysics is therefore interested in topics like:
the existence of God, the nature of reality, the
concept of ‘Ori’, freedom and determinism, mind
and body relation, life after death, and so on. The
scope of metaphysics is so wide that Richard
Taylor, says: “Because metaphysics deals with
everything, we cannot specify any particular object
as its exclusive subject matter.”

ORIGIN OF METAPHYSICS
•What is known today as metaphysics
began with a disciple of Aristotle called
Andronicus. Andronicus did the collection
of the works of Aristotle in his life time
and called it Physics. However, after this,
he found some other works of Aristotle
apart from the ones already put together
and called Physics.

ORIGIN OF METAPHYSICS CONT
•When he did the collection of the
second volume and did not know what
to call it, he gave it the name,
Metaphysic. That, the book written after
Physics. Note however that Aristotle in
his life time did not call his works
metaphysics but First philosophy.

MIND/BODY PROBLEM
•It is generally believed among Greek writers
and philosophers that man is made up of
matter and spirit, soul and body. It was Rene
Descartes however that first critically
examined the composition of a man as having
body and mind. This examination he did in his
book Meditation VI.

MIND/BODY PROBLEM CONT
•According to him, a man is made up of two
entities that are radically different by their
nature and function. The body that is physical,
material and performs the function of
extension and occupies space. The other is the
mind that is spiritual, immaterial and
performs the function of thought.

• What is called mind/body problem is not whether or
not two entities exist. It deals with the nature of
interaction between these entities, bearing in mind that
they are radically different in nature. How is it possible
for the mind to control the body or the body control
the mind? How come that when it comes to the mind
of a student sleeping in his hostel that he has a lecture at
a particular hour and he immediately decides and takes
action to attend the lecture?

•Descartes could not provide answer to the
mind/body problem or his answer was
not satisfactory. He only said that the
point of interaction between them is at
the Pineal Gland. But the question is not
about where but how.

SPINOZA’S RESPONSE TO MIND/BODY PROBLEM
•Those who hold that mind and body and distinct
and separate entities are called dualists, examples
of whom are Descartes and Baruch Spinoza.
According to Spinoza, the body is an entity and
the mind is another entity. Each of them is a
monad which he describes as windowless. The
body as a monad is designed by God to act on its
own without knowing that another monad, that
is, the mind exists because it is windowless.

SPINOZA’S RESPONSE TO MIND/BODY
PROBLEM CONT
•The mind, another monad, was also designed by God
to think, not aware of the existence of the other
monad, that is, the body. But, God, though what
Spinoza calls the principle of Pre-established harmony
has so designed them to operate is such a way that
when one monad acts, the other also acts. One
problem with this solution is that, which one controls
the other? Also, we find out that sometimes, the mind
thinks but the body fails to act accordingly.

GILBERT RYLE’S RESPONSE TO THE MIND/BODY
PROBLEM
•Ryle is a Monist, a name given to those
philosophers who hold that only one
entity, mostly, the body exists. According
to Ryle, those who hold that the mind
exists apart from the body commit a
Categorical Mistake. He likens them with a
man who was visiting the Oxford
University for the first time.

GILBERT RYLE’S RESPONSE TO THE MIND/BODY
PROBLEM CONT
•The man was shown the gate, Library,
hostels, administrative blocks and lecture
rooms of the university. But the man said,
I have seen the buildings, but: where is the
university? Ryle submitted that it is the
body that thinks and acts

PHILOSOPHICAL ARGUMENT FOR GOD’S
EXISTENCE
•Philosophers believe that God exists, contrary
to the thought of many laymen. They also
believe that man can know that God exists
without being a religious person. There are
rational arguments that proves His existence.
We are going to consider three of them in this
course. These are: ontological, cosmological
and moral arguments

ONTOLOGICAL ARGUMENT
•St Anselm is the chief exponent of this argument.
According to him, one must seek to believe in
order to understand, and that was what he sets
out to do in this argument. To know that God
exists, Anselm says, let us imaging those things in
the world. One thing is great, another is greater,
yet another is great. One is good, another is
better, yet another is good.

ONTOLOGICAL ARGUMENT CONT
•Then, let us enter into the inner chamber
of our heart, shut the door, imagine the
greatest thing in the world. Let’s imagine
further something that is greater than
what we imagine to be the greatest. That
thing that is greater than the greatest we
imagine is God.

•To support his argument, Anselm quoted
Psalm 14: that says: the fool says in his heart
that there is no God. What make the fool a
fool is not because he does not believe but
because he involves himself in contradiction.
This is someone who mention ‘God’, and
according to Anselm, he still goes ahead to
say that what he mentions does not exist.

•. The fool forgets, according to Anselm,
that existence is a predicate of God. The
one who says that God does not exist is
saying that what exist does not exist, a
sheer contradiction. With this, Anselm
thought that he has proved that God
exists.

•It was his disciple, Gaunnilon who first
pointed out we can imagine many things
but that imagination does not amount to
existence, after all we can imagine a
perfect island that does not actually exist.

THE COSMOLOGICAL ARGUMENT
•FROM MOTION.
•FROM CAUSE.
•FROM BEING.
•FROM DESIGN.
•FROM PERFECTION.

THE MORAL ARGUMENT
•Immanuel Kant is associated with the moral
argument for the existence of God. According to
him, we live in the world of phenomena. In this
world, there are high levels of injustice. Yet, the
law of justice holds that everyone reaps what he
sows, good or bad. But, there are those who
suffer and died for the crime they did not
commit. There are good people who suffer
innocently. There are also known bad and
criminals who escape punishments.

THE MORAL ARGUMENT CONT
•Yet, the law of justice can never fail.
There must therefore be another world
called Noumena where everyone, good
or bad, will be accordingly rewarded
according to his deeds. The person that
will reward everyone accordingly is God.
Therefore, God exists.

EXISTENTIALISM AND EXISTENCE
•Existentialism is the aspect of philosophy
that came as a reaction to the traditional
philosophy. It is taken from the word
‘exist’ which means ‘to be’ or ‘to be out
there.’ It holds that before we know the
world out there, there is the need to
know who we are.

EXISTENTIALISM AND EXISTENCE CONT
•It seeks to find answers to questions like:
how do we find ourselves in this world?
Are we free or determined? What is
human nature? Is there life after death?
What is the purpose of life? Is this the only
world? What is death and should it be
feared or not?

•Existentialism was founded by a Danish
philosopher, Soren Kierkegaard while the
most known and most astute existentialist
is Jean Paul Sartre. Other notable
existentialists are: Friedrich Nietzsche,
Edmund Husserl, Martin Heidegger,
Martin Buber, Karl Jasper, Gabriel Marcel,
Albert Camus and so forth

•Existentialists are usually classified into theists
and atheists. Those who build their
existentialism around God, such as:
Kierkegaard, Heidegger and Maurice, are
called theistic existentialists and those who did
not put God at the centre of their thought are
the atheistic existentialists and they include
Sartre, Camus and Nietzsche, though, not
necessarily they did not believe in Him.

•Soren Kierkegaard’s greatest contribution to
existentialism is his claim about knowledge.
According to him, knowledge is a miracle and
it is possible only by the help of God. Man, in
order to know, must therefore be involved in
what he calls leap of blind faith. No man,
according to him, can prove God’s existence.
He simply just exists whether or not one
believes.

SARTRE’S EXISTENTIALISM
•Man is a Possibility.
•Human Freedom.
•Existence and Essence.
•Bad Faith.
•Responsibility.
•Facticity.
•Death.

Philosophy, Logic and Human Existence.pptx

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