Law of contradiction states that :
Nothing can be both (A) and not (A)
Traditional logic recognises three laws of thought: the law of identity, the law of non-contradiction (contradiction) and the law of excluded middle.
The law of contradiction states that nothing can be both A and not A at the same time and in the same respect; symbolically, ~ (p • ~ p). No proposition can be both true and false.
“Everything is identical to itself” is the law of identity; “Everything is either A or not A” is the law of excluded middle; and “Proposition can be both true and false” denies the law of contradiction rather than stating it.
Hence, the answer is Nothing can be both (A) and not (A).
Similar Questions
Match List I and List II and select the correct answer from the codes given below :
List I List II (a) ~ (p ∨ ~ p) (1) Identity (b) ~ (p • ~ p) (2) Contingency (c) ~ (p ⊃ q) (3) Tautology (d) p ⊃ p (4) Contradiction Codes :
(a) (b) (c) (d)
Which of the following is not the characteristics of an effective decision procedure ?
Correct formulation of the Rule U.I. (Universal Instantiation) is ........... .
Characteristics of an Axiomatic systems are ................. .
(1) Consistency
(2) Completeness
(3) Independence
(4) Contingent
Correct symbolization of the following proposition is — “All successful politicians and orators are hard-working”.
“Sudhir had not locked the gates yesterday. Either the watchman or Sudhir locks the gates. Therefore, the watchman must have locked the gates yesterday”. This argument is ..................... .
If the statement ‘p’ is true and the statement ‘q’ is false, the truth value of the statements ‘p ≡ ~ q’ and ‘~ q ⊃ ~ p’ are :
In the ranking of a competitive examination Vishal was above Vijay but below Shyam. Mohan was above Shyam but below Rohan. Vijay was between Vishal and Ashok. Who is third from the top ?
Ragini facing East walks 10 meter, then she turns to her left and walks 12 meter. Then she turns to her right in $45^o$ and walks 15 meter. Then, how much distance she has walked from the starting point and which direction is she facing now ?
In the Wason selection task for propositional reasoning, ‘participants develop a general idea of the rule, then construct examples that follow the rule’ is referred to as :
Important Questions from Deductive - Teaching
Match List I and List II and select the correct answer from the codes given below :
List I List II (a) ~ (p ∨ ~ p) (1) Identity (b) ~ (p • ~ p) (2) Contingency (c) ~ (p ⊃ q) (3) Tautology (d) p ⊃ p (4) Contradiction Codes :
(a) (b) (c) (d)
Which of the following is not the characteristics of an effective decision procedure ?
Correct formulation of the Rule U.I. (Universal Instantiation) is ........... .
Characteristics of an Axiomatic systems are ................. .
(1) Consistency
(2) Completeness
(3) Independence
(4) Contingent
Correct symbolization of the following proposition is — “All successful politicians and orators are hard-working”.
