5. The logical principles to print

Name: ______________________________________  Subject: _______________________ Date: _______

Write on the right side what is missing.

1. Principle of identity

We can say that showing it we make to see the truth based on another previous thuth and clearer.

The logical principles are the first thruths in which are based all the others. It is allowed without hesitation because they are obvious and clear.

They are four: principle of identity, principle of contradiction, principle of the third excluded and principle of enough reason.

The principle of identity says that what is really. Example: the table is the table. The things are identical to themselves.

In a judgement, if the predicate is identical to the subject, it is really true. I am me. It is clear and obvious.

A. Answer with one of these letters: a, b, c.

 1. If a truth is based on another it is a. showing     b. perception     c. sensation 2. The logical principles are the truth a. third     b. second     c. first 3. The logical principles are the truth a. unclear     b. obvious and clear     c. doubtful 4. The logical principles are a. six     b. five     c. four 5. What is really; it means the principle of a. identity     b. contradiction     c. third excluded 6. The predicate and the subject are a. similar     b. identical     c. different

What something is really, it can't be the opossite at the same time. Nothing can be one thing and not be something at the same time: Juan is tall and Juan is not tall. Juan can't be two things at the same time. He is tall or he isn't tall but not both of them at the same time.

The principle of contradiction points that in two judgements the subject and predicate are contradictory, both of them can't be true. In other words: it is impossible that something be and not be anything at the same sense.

In the contradictory predicates, one is affirmative and the another is negative: big and not big.

The contradictory predicates are both affirmative: the pen is big, the pen is small.

Principle of the third excluded. When the predicates are contrary, there is a third possibility: that the predicate be medium.

Another example: the car can be white, red, blue or black. Between the white and the black there are many colours.

The principle of contradictory says that between the white and nonwhite there isn't any colour. But in the nonwhite there are the rest of the colours.

B. Answer with one of these letters: a, b, c.

 1. What something is, it can't be the opposite at he same time a. Principle of: identity     b. contradiction     c. third excluded 2. Juan is tall or isn't tall according to the principle of a. contradiction     b. identity     c. third excluded 3. The table is the table. Its is the principle of a. contradiction     b. third excluded     c. identity 4. Two judgements can't be true if the predicates are a. contradictory     b. contrary     c. parecidos 5. Two judgements can be true if the predicates are a. contradictory     b. contrary     c. parecidos 6. Between the white and nonwhite there isn't any colour according to the principle of a. identity     b. third excluded     c. contradiction

3. Principle of enough reason

Everything that is, everything that happens, there is an enough reason. All has an enough reason.. This can be applied to the natural order, logical and moral.

a) In the natural order, when this principle is applied to the physical things, it means that all exists by some cause, it means, “every effect has its cause”. Example: The heat (cause) expands the bodies (effect). Also other things have causes like the raining, the strength of the steam of the water, etc. In general, every real being has its cause.

b) In the logical order, this principle means that “everything has its reason”.Example: If A = B, B = C, then A= C, the reason that A is equal to C is that A is equal to B and B is equal to C.

In Mathematics is also used the term reason and not cause. The proofs of mathematics are chains of reasons.

c) In the moral order this principle says: “Every human action has its reason”. If we are studying is for something, for some reason; for some reason we read or go for a walk.

C. Answer with one of these letters: a, b, c.

 1. Everything that is, there is a reason a. questionable     b. possible     c. enough 2. If it is applied to the physical things we are in the order a. natural     b. logical     c. moral 3. Every human action has its reason. This is order a. logical     b. moral     c. natural 4. Everything has its reason. This is order a. natural     b. logical     c. moral 5. In mathematics is used the term a. cause     b. possibility     c. reason 6. The causes and effects are seen in the order a. natural     b. logical     c. moral

| Educational applications | Philosophy |  For young | In Spanish | Interactive |

®Arturo Ramo García.-Record of intellectual property of Teruel (Spain) No 141, of 29-IX-1999
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