The tools for distinguish between
true and false. ( AVERROES )
The sceinse as well as art of
reasoning. ( J.R WATSON )
The history of logic is the study of
the development of the science of
valid inference (logic). logic was
developed in ancient times
in China, India, and Greece. Greek
logic, particularly Aristotelian logic,
found wide application and
acceptance in science and
HISTORY OF LOGIC
In philosophy, term logic, also known
logic or Aristotelian logic.
Aristotle's logic was further developed
by Islamic and Christian philosophers in
the Middle Ages, reaching a high point in
the mid-fourteenth century. The period
between the fourteenth century and the
beginning of the nineteenth century was
largely one of decline and neglect, and
is regarded as barren by at least one
historian of logic.
Progress in mathematical logic in
the first few decades of the twentieth
century, particularly arising from the
work ofGödel and Tarski, had a
significant impact on analytic
philosophy and philosophical logic,
particularly from the 1950s to
PROGRESS IN LOGIC
The other great school of Greek logic is
that of the Stoics. Stoic logic traces its
roots back to the late 5th century BC The
most important member of the school
was Chrysippus. (206– 278 BC) who was
its third head.
SCHOOL OF LOGIC
None of the surviving works of the great fourth-century
philosopher Plato (347–428 BC) include any formal
logic but they include important contributions to the field
of philosophical logic. Plato raises three questions:
1-What is it that can properly be called true or false?
2-What is the nature of the connection between the
assumptions of a valid argument and its conclusion?
3-What is the nature of definition?
In China, a
of Confucius, Mozi
, "Master Mo", is
the Mohist school.
LOGIC IN ASIA
Logic began independently inIndia and
continued to develop through to early
modern times, without any known
influence from Greek
logic.Gautama (6th century BC)
founded the tarka school of
logic.The Mahabharata around the 5th
century BC, refers to tarkaschools of
logic. Panini (5th century BC)
The works of Al-Kindi, Al-Farabi, ibn
sina, Al-Ghazali, and other Muslim
were important in communicating
the ideas of the ancient world to the
middle West.Al-Farabi (Alfarabi)
(873–950) was an logician who
discussed the topics
between logic and grammar.
Logic in the Middle East
Ibn Sina (Avicenna) (980–1037)
Fakhr al-Din al-Razi(b. 1149)
Nasir al-Din al-Tusi(1201–1274)
A text by ibn sina
MIDDLE EAST PHILOSOPHERS
logic generally means
the textbook tradition
with Annual and Pierre
Nicole's Logic, or the Art
of Thinking, better
known as the Port-Royal
The Textbook Tradition
10 GREAT PHILOSOPHER IN THE HISTORY
3-Paul of Tarsus
8-Zeno of Citium
Plato lived from 348 to 428 BC, and
founded the Western world’s first school of
higher education, the Academy of logic.
3-Paul of Tarsus
Descartes lived from 1596 to 1650, and
today he is referred to as “the Father of
Modern Philosophy .
Master Kong Qiu, as his name translates
from Chinese, lived from 479 to 551 BC,
and remains the most important single
philosopher in Eastern history.
Thomas proved the existence of God by
arguing that the Universe had to have
been created by something, since
everything in existence has a beginning
and an end. He made five famous
arguments for the existence of God.
His full name is Abu ʿAli al-
Husayn ibn ʿAbd Allah ibn
Sina, He lived in the Persian
Empire from. 980 to 1037 BC.
8-Zeno of Citium
Locke is referred to as the
“Father of Liberalism,”
because of his development
of the principles of humanism
and individual freedom.
Rise of modren logic
The period between the fourteenth century and
the beginning of the nineteenth century had been
largely one of decline and neglect, and is
generally regarded as barren by historians of
logic.The revival of logic occurred in the mid-
nineteenth century, at the beginning of a
revolutionary period where the subject
developed into a formalistic discipline whose
exemplar was the exact method of proof used
in mathematics. The development of the modern
so-called "symbolic" or "mathematical" logic
Three Basic Functions are generally
noted: there is perhaps nothing more
subtitle than language is and nothing
has as many different uses.
Without a doubt, identifying just
these Three basic functions is an
over simplification, but an awareness
of these functions is a good
introduction to the complexity of
1-Informative language function:
essentially, the communication of
a. The informative function affirms or
denies propositions, as in science.
The Functions of Language
b. This function is used to
describe the world or reason
about it (e.g… whether a state
of affairs is true or false).
c. These sentences have a
truth value; hence, they are
important for logic.
function: reports feelings or
attitudes of the writer (or speaker),
or of the subject, or evokes feelings
in the reader (or listener).
a. Poetry is one of the best
examples, but much of, perhaps
most of, ordinary language
discourse is the expression of
emotions, feelings or attitudes.
b. Two main aspects are generally
noted : (1) to evoke certain
feelings and (2) to express
Expressive discourse, qua
expressive discourse, is best
regarded as neither true or false.
E.g., Shakespeare's King Lear's
lament, "Ripeness is all!" Even so,
the nature of "fictional statements"
3.Directive language function:
language used for the purpose of
Causing (or preventing) overt actions.
a. The directive function is most
commonly found in commands and
b. Directive language is not normally
considered true or false (although a logi
of commands have been developed).
c. Example: "Close the windows."
Many of the most common
words and phrases of any
language have both a literal or
descriptive meaning that refers
to the way things are and an
emotive meaning that expresses
some (positive or negative)
feeling about them.
FACTORS OF COMMUNICATION
AND FUNCTIONS OF LANGUAGE
According to Jakobson any act of
verbal communication is composed
of six elements, or factors (the terms
of the model):1) a context (the
co-text, that is, the other verbal
signs in the same message, and the
(2) an addresser (a sender, or
(3) an addressee (a receiver, or
(4) a contact between an
addresser and addressee.
(5) a common code and
(6) a message.