In Classical Square of Opposition, if 'Some S is not P' is true then which of the following could be immediately inferred from it?
A. 'Some S is P' is false
B. 'All S is P' is false
C. 'No S is P' is undetermined
D. 'Some S is P' is undetermined
E. 'All S is P' is undetermined
Choose the correct answer from the options given below:

Correct option is B

In the Classical Square of Opposition, the proposition 'Some S is not P' is a particular negative proposition (O-type).
B ('All S is P' is false): This can be inferred. If 'Some S is not P' is true, it directly contradicts 'All S is P' (a universal affirmative proposition). Therefore, 'All S is P' must be false.
C ('No S is P' is undetermined): This is correct. The truth of 'Some S is not P' does not provide information about whether all S's are excluded from P, making 'No S is P' undetermined.
D ('Some S is P' is undetermined): This is correct. 'Some S is not P' does not determine whether some S's are P or not. Both 'Some S is P' and 'Some S is not P' can be true at the same time. Therefore, it remains undetermined.
Information Booster 1. Classical Square of Opposition:
· A-type (Universal Affirmative): All S is P
· E-type (Universal Negative): No S is P
· I-type (Particular Affirmative): Some S is P
· O-type (Particular Negative): Some S is not P
2. Key Relationships:
· Contradictory: A and O; E and I (one true, the other false).
· Contrary: A and E (cannot both be true, but both can be false).
· Subcontrary: I and O (cannot both be false, but both can be true).
· Subalternation: Truth of A implies I; truth of E implies O.
3. Immediate Inferences:
· From 'Some S is not P' (O-type):
· 'All S is P' (A-type): False
· 'Some S is P' (I-type): Undetermined
· 'No S is P' (E-type): Undetermined