What knowledge is applicable to more than one thing?
Any property which can be found in more than one thing is a common property. Any property which cannot be found in more than one thing is a special property.
The knowledge of the common properties is applicable to more than one thing because a common property can be found in more than one thing. The knowledge of a special property is not applicable to more than one thing because a special property cannot be found in more than one thing.
No knowledge is applicable to more than one thing if things have no common property. Is no knowledge applicable to more than one thing? No knowledge can be applied by more than one person in the absence of common properties among things. Is no knowledge used by more than one person?
Nothing can be studied without the knowledge of its properties. Students should learn how to use the knowledge which is applicable to more than one thing in their studies. Teachers should illustrate to students how the knowledge of the common properties is applicable to more than one thing and the students should be provided with the explicit list of common properties of known things. Why should not students learn to use the knowledge which is applicable to more than one thing?
Everyone who proclaims that things have no common properties would not explain: i. how a knowledge is applicable to more than one thing, and ii. how a knowledge can be used by more than one person.
How can a knowledge be applicable to more than one thing if things have no common property?
