Given below are two statements

Statement I: 'Some S is P' is contrary to 'No S is P'.

Statement II: 'Some S is P' is subcontrary to 'Some S is not P'.

In light of the above statements, choose the correct answer from the options given below

The correct option is Statement I is false but Statement II is true

Important Points

• In logic and philosophy, "contrary" and "sub contrary" are terms used to describe the relationship between two statement
  • Statement I: 'Some S is P' is contrary to 'No S is P', which means that these two statements cannot both be true simultaneously.
  • They are the opposite in meaning and cannot both be true simultaneously.
• Statement II: 'Some S is P' is sub contrary to 'Some S is not P', which means that these two statements cannot be false simultaneously. They are opposite in meaning and cannot both be false simultaneously.
• In other words, if one of the statements is true, the other must be false, and vice versa.

Key Points

In logic, the Square of Opposition is a diagram that shows the relationships between four standard forms of categorical propositions. The four standard forms are:

• A (universal affirmative) - "All S is P"
• E (universal negative) - "No S is P"
• I (particular affirmative) - "Some S is P"
• O (particular negative) - "Some S is not P"

According to the Square of Opposition, the relationships between these four forms are as follows:

• A is logically contrary to E.
• I is logically sub contrary to O.

This means that if one of the statements is true, the other must be false. The two statements cannot both be true or false at the same time.

So, Statement I: 'Some S is P' is contrary to 'No S is P' is true according to the Square of Opposition, and Statement II: 'Some S is P' is sub contrary to 'Some S is not P' is also true according to the Square of Opposition.