Scope of Logic & Inductive and Deductive Logic

In logic, "argument" does not have the common connotation of dispute (no shouting or name calling involved!). Argument is simply statements that support a conclusion. Logic does not deal with truth or the persuasive power of argument. Logic is only concerned with an objective relationship between argument and conclusion.

Scope:
An argument is a group of statements standing together.
e.g. From Sherlock Holmes:
1. This is a large hat.
2. Someone is the owner of this hat.
3. Owners of large hat have large heads.
4. People with large head large brains.
5. People with large brains are highly intellectual.
6. Owner of this hat is highly intellectual.

First 5 statements are premises; the sixth one is a conclusion.

Here 2 questions arise:
1) Are the premises correct?
2) Are the premises properly related to the conclusion?
Logic is concerned with the second question only.

Scope of Logic: Logic deals with the relation between premises and conclusion, not with the truth of the premises.

Deductive vs. Inductive Logic
Deductive Logic:
e.g. Every mammal has a heart.
All horses are mammals.
Every horse has a heart.

If all of the premises are true, the conclusion is true.
All of the facts in the conclusion are already contained, at least implicitly, in the premises.
Purpose of deductive logic is to highlight the contents of the premises.
Deductive logic is either entirely conclusive or entirely inconclusive...mathematical arguments are deductive.

Inductive Logic:
e.g. Every horse that has ever been observed has had a heart.
Every horse has a heart.

If all of the premises are true, the conclusion is probably true but not necessarily true.
Conlcusion contains information (facts) not present, even implicitly, in the premises.
Purpose of inductive logic is to extend the range of knowledge.
Inductive logic admits a degree of strength depending upon the level of support premise provides to the conclusion...the relation between a scientific generalization and its supporting observational evidence is inductive logic.

Source: Logic - Wesley C. Salmon. Pub. Prentice Hall Inc. 1963

Quote: Do what you think is right.

This occurred during my early "Registrar" days in Chatham, Kent.

I managed a preterm baby's ventilation using certain strategy overnight. Next morning, while on rounds, consultant asked why I used such strategy. I answered, I thought he would manage it that way. He did not say anything further. But after rounds, he took me into this office and said the following: "When you manage a patient in the middle of the night or any other time, manage according to what you think is right. So, the decisions made will be right according at least one person. Last night, you used that strategy thinking I would like it that way. But, I think, you should have used the other strategy. Now, the decision is not right by either of us! In such situations if you make decision and carry it out according to what you think is right, it would be right at least by one of us - you. It is better to have a decision/treatment strategy that is right by at least one of us rather than neither of us."

I paraphrased it. Tony Ducker was the consultant rounding that morning.

Quote: Classical Music

Classical music is th'kind that we keep thinking'll turn into a tune.

Frank McKinney (Kin) Hubbard
Comments of Abe Martin and his neighbors (1923)

Quote: Old age (Bernard Baruch)

To me old age is always fifteen years older than I am.
(Bernard Baruch, 1870-1965, Newsweek Aug 29, 1955)

Other quotes from him:
Vote for the man who promises least; he'll be the least disappointing. (1960)

You can talk about capitalism and communism and all that sort of thing, but the important thing is the struggle everybody is engaged in to get better living conditions, and they are not interested too much in forms of government. (1964)

Source: Oxford Dictionary of Modern Quotations.

Quote: Communication

One who forms a judgement on any point but cannot explain it clearly might as well never have thought at all on the subject.

(This quote is attributed to ancient Greek Leader Pericle, 2500 years ago)

Time: A daily miracle!

Time is the inexplicable raw material of everything. With it, all is possible; without it, nothing.

Supply of time is truly a daily miracle, an affair genuinely astonishing when one examines it. You wake up in the morning, and lo! your purse is magically filled with "twenty-four hours" of the unmanufactured tissue of the universe of your life! It is yours.


It is the most precious of possessions. A highly singular commodity, showered upon you in a manner as singular as the commodity itself.


No one can take it from you.
No one receives more or less than you receive.


Talk about ideal democracy! In the realm of time, there is no aristocracy. Genius is never rewarded by even an extra hour a day.


And, there is no punishment. Waste your commodity as much as you will, and the supply will never be withheld from you.


Payment will not be affected by Sundays.


And, you can not draw on the future. So, impossible to get into debt. You can only waste the passing moment. You can't waste tomorrow; it is kept for you. You can't waste the next hour; it is kept for you.


(I will stop there...I start to disagree here, at that last couple of statements. You can draw on the future by postponing today's work or this hour's work into the next one!)

From How to live on 24 hours a day - Arnold Bennett

First published in 1930s

Quote: Success and Failure

Many of life's failures are people who did not realize how close they were to success when they gave up.

Thomas A. Edison

Tag line in Prakasam's email signature.

Quote: Power to concentrate

Without power to concentrate - that is to say without power to dictate to the brain its task and to ensure obedience - true life is impossible. Mind control is th first element of a full existence.

From "How to live on 24 hours a day" Arnold Bennett.

First published in 1930s.