of which are intended to provide support, justification or evidence
for the truth of another statement or proposition. Arguments consist
of one or more premises and a conclusion. The premises are those
statements that are taken to provide the support or evidence; the
conclusion is that which the premises allegedly support. For example,
the following is an argument:
The death penalty should be adopted only if it deters murder.
However, it could only do this if murderers understood the
consequences of their actions before acting, and since this is not so,
we must reject adopting the death penalty.
The conclusion of this argument is the final statement: "we must
reject reject adopting the death penalty." The other statements are
the premises; they are offered as reasons or justification for this
claim. The premises of an argument are sometimes also called the
"data," the "grounds" or the "backup" given for accepting the
conclusion.
Because arguments are attempts to provide evidence or support for a
certain claim, they often contain words such as "therefore," "thus,"
"hence," "consequently," or "so" before their conclusions. Similarly,
words or expressions such as "because," "inasmuch as," "since," "for
the reason that," etc., are often found accompanying the premises of
an argument. Such "indicators" can aid in the task of identifying the
conclusion of the argument, which often comes last in the series of
statements making up the argument, as in the example above, but can
also come first, or even in the middle, such as in these examples:
Councilwoman Radcliffe is the best person for the job. This is
because she has the most legislative experience of all the candidates,
and she will not place the interests of corporations above those of
the people.
Callisto orbits Jupiter. Hence, it is not a planet, because
something must orbit a star in order to be a planet.
In the examples above, the italicized statements are the conclusions.
The other statements are offered as reasons or justifications for
these claims.
In everyday life, we often use the word "argument" to mean a verbal
dispute or disagreement. This is not the way this word is usually used
in philosophy. However, the two uses are related. Normally, when two
people verbally disagree with each other, each person attempts to
convince the other that his or her viewpoint is the right one. Unless
he or she merely results to name calling or threats, he or she
typically presents an argument for his or her position, in the sense
described above. In philosophy, "arguments" are those statements a
person makes in the attempt to convince someone of something, or
present reasons for accepting a given conclusion.
In normal conversation, certain important elements of an argument
might be left implicit or unstated. In the last example given above,
the person advancing the argument most likely takes it for granted
that his or her audience understands that if something orbits Jupiter,
then it does not orbit a star. This supposition is a vital part of the
evidence or support that the author intends the stated premises to
provide for the conclusion. Here, the statement "if something orbits
Jupiter, then it does not orbit a star" is operating as an implicit or
unstated premise. Therefore, the above argument is best understood as
an abbreviated form of the full argument:
Callisto orbits Jupiter. Something must orbit a star in order to
be a planet. If something orbits Jupiter, then it does not orbit a
star. Therefore, Callisto is not a planet.
Even the conclusion of an argument can be left unstated if it is
obvious enough from context that the speaker intends his or her words
to provide evidence for a certain proposition. Consider, for instance:
Only children are allowed on the swingset, and Ms. Peabody, you
are no child, are you?
Here, the speaker is obviously inviting Ms. Peabody to draw the
conclusion that she is not allowed on the swingset.
Normally, a single statement in isolation does not constitute an
argument, but simply a declaration or assertion. For example, if a
teacher simply announces at the beginning of a class "Councilwoman
Radcliffe voted in favor of the tax increase," she is not arguing for
a given conclusion; she simply intends her students to accept her
assertion on its own. However, in the right context, a single
statement can abbreviate a whole argument if the other implicit pieces
of the argument are clear from the context. In a discussion among
conservative politicians discussing whom they'd like to see as the
next candidate for Senator, where it is agreed by all participants
that no one who supports increased taxes is a desirable candidate,
someone might implicitly be arguing against Radcliffe's candidacy with
the simple statement, "Councilwoman Radcliffe voted in favor of the
tax increase." When the implicit premise and implicit conclusion are
filled in, the argument in its entirety could be stated in this way:
Councilwoman Radcliffe voted in favor of the tax increase. No one
who voted in favor of the tax increase is a desirable candidate.
Therefore, Councilwoman Radcliffe is not a desirable candidate.
In an argument, the premises are almost always put forth or claimed to
provide support for the conclusion; however, the premises do not
always actually provide support. If we take as our example the
following argument:
The roulette wheel has landed on red the last five spins.
Therefore, since black is "due," the next spin will probably be black.
The person stating this argument probably thinks that the conclusion
is justified by the premise, but he or she would be mistaken. The
reasoning here is fallacious. The premise could be true without the
conclusion being definitely or even probably true. However, this is
still an argument, because the premise is at least intended to provide
support or evidence for the conclusion, even if it does not.
Logicians study the criteria to be used in evaluating arguments, i.e.,
the criteria for determining under what conditions a certain set of
premises actually guarantees the truth or likely truth of the
conclusion.
Arguments are related to inference and reasoning: i.e., the
psychological process through which a person forms a new belief on the
basis other beliefs. A course of reasoning can usually be recast or
reconstructed as an argument. For example, if someone already believed
that all Romance languages were derived from Latin, and then learned
that Rumanian was a Romance language, she or he would likely form the
new belief that Rumanian was derived from Latin. If this person were
to express her or his train of thought out loud or write it down, it
would take the form of this argument:
All Romance Languages are derived from Latin. Rumanian is a
Romance Language. Therefore, Rumanian is derived from Latin.
However, it should not be thought that the psychological process of
inference or the nature of cognition are relevant to the evaluation of
arguments. Regardless of whether or not the argument above corresponds
to anyone's psychological process or cognitive behavior, it can be
analyed by logicians as valid, because the premises do provide support
for the conclusion.
Arguments must be separated off from other uses of language, such as
to explain something, give an example, or tell a story. In these
cases, one might find a connected series of statements, but the author
or speaker does not intend it to be the case that some of them provide
support or evidence in favor of one of the others. So they are not
arguments. Consequently, one must distinguish arguments fromreports of
arguments. If a newspaper journalist includes in her article a
description of an argument given by Senator Feingold in favor of
campaign finance reform, the reporter is not herself arguing in favor
of campaign finance reform nor anything else. She is merely making a
report.
There are other uses of language that may appear at first blush to be
arguments, but are not. Such is the case with explanations. Sometimes
it is agreed by participants in a conversation that a certain event
has taken place, or that a certain thing is true. Suppose, for
example, it is agreed that Alex is late for his job. Someone might
explain this fact as follows:
Alex's car broke down yesterday, and without it he cannot get to
work on time. Therefore, he is late for work today.
The above may appear to be an argument. In fact, it has the same
structure as an argument, and even includes the indicator "therefore."
However, notice that the person speaking these words is not attempting
to provide support or evidence for the truth of the claim that "Alex
is late for work today:" that is already accepted as true in this
context by everyone involved. Properly speaking, the above example is
an explanation, not an argument. However, in another context, in which
it was not generally known that Alex is late for work today, these
very words could be used as an argument. Consequently, it is
impossible to ascertain whether or not a certain utterance is an
argument without ascertaining the speaker's intentions within the
given context. (For more on the relationship between arguments and
explanation, see the article on "Scientific Explanation.")
Much of philosophy consists in the evaluation of particular arguments,
some simple, some complicated. Descartes's famous three word saying,
"cogito ergo sum" (I think, therefore I am) represents an extremely
compact argument, with a single premise, that he is thinking, to the
conclusion that he exists. Other philosophical arguments are more
complicated and elaborate. Consider the following argument from
Plato's Apology:
Let us reflect in another way, and we shall see that there is
great reason to hope that death is a good, for one of two things: —
either death is a state of nothingness and utter unconsciousness, or,
as men say, there is a change and migration of the soul from this
world to another. Now if you suppose that there is no consciousness,
but a sleep like the sleep of him who is undisturbed even by the sight
of dreams, death will be an unspeakable gain. For if a person were to
select the night in which his sleep was undisturbed even by dreams,
and were to compare with this the other days and nights of his life,
and then were to tell us how many days and nights he had passed in the
course of his life better and more pleasantly than this one, I think
that any man, I will not say a private man, but even the great king,
will not find many such days or nights, when compared with the others.
Now if death is like this, I say that to die is gain; for eternity is
then only a single night. But if death is the journey to another
place, and there, as men say, all the dead are, what good, O my
friends and judges, can be greater than this? If indeed when the
pilgrim arrives in the world below, he is delivered from the
professors of justice in this world, and finds the true judges who are
said to give judgment there, Minos and Rhadamanthus and Aeacus and
Triptolemus, and other sons of God who were righteous in their own
life, that pilgrimage will be worth making. What would not a man give
if he might converse with Orpheus and Musaeus and Hesiod and Homer?
Nay, if this be true, let me die again and again.
Here the character Socrates argues for the conclusion that death is a
good. The justification he offers for the conclusion, however, is
rather elaborate; he offers quite a few premises, which, taken
together, are thought to provide support for the conclusion.
Note: There is another, completely distinct, use of the word
"argument," that can also be relevant to logic, specifically, to the
logic of functions and relations. An argument to a function is
contrasted with the value of that function. Loosely speaking, the
argument is the input, the value is the output. When the square root
function takes 9 "as argument," the value is 3. When it takes 16 "as
argument," the value is 4. Different functions take a different number
of arguments. The square root function takes a single argument;
whereas addition and multiplication require two arguments to yield a
value. I.e., in the equation, x + y = z, x and y are the arguments to
the addition function, and z is the value. Sometimes, logicians also
speak of predicates and relations as having a certain number of
"argument-places." For example, the relation expression "___ is taller
than …" is said to have two argument places, because it requires
completion by two terms to form a complete proposition.
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