unlikely likeness

When comparing two or more entitites , the subjects tend to find the similarities or dissimilarities in observable characteristics of the entities to come up with the conclusion about their likeness or unlikeness. This process is applicable unless the subject comes to a conclusion of complete likeness or complete unlikeness about the entities. Because, If the entities are completely alike, then why would there be more than one entity in the first place. All entities, at the highest level of generalization have their existence in the objective world as a common observable characteristic among them.But for the entities' existence, the subjects wouldn't have anything to compare. So,if we conclude that an entity A is completely unlike entity B, then it means that one of them is bound to loose its characteristic of existence.That is , one of the entitites is nonexistent. So there is no absolute likeness or unlikeness among entities that are compared.There is only a degree of likeness or unlikeness in their observable characteristics. This is a nice new idea (for me) from the book "Being Logical".The book says that an idea has no existence unless expressed, So here I tried to express it.