Let’s begin with something else. When we talk of ‘change’, it is by definition, change in the same thing – the same specific property of something.
When we compare 2 things, we can only compare their same corresponding properties. You cannot compare the weight of a book with the colour of a chair. So, when we say there is a similarity or a difference between 2 things, it is so between the same properties of the 2 things.
The above leads us to the definition of a link – a typical connection between 2 entities :
When 2 DIFFERENT properties of 2 entities are same/common, there is a link between the 2 entities.
In fact, if there is a sameness between any 2 properties (one of each) of 2 entities, there is a link between the 2. In the second sentence, the definition is broadened to ANY 2 properties; that includes similarities as described in the first paragraph, as subsets of connections/links.
If a chair is made of silver and a book has its name written on it in silver colour, there isn’t any similarity between the 2 entities since different properties of the 2 entities bear sameness (material making up one and colour of ink of text written on the other) with each other, but a link.
The spotting of links between 2 entities is generally of value while thinking, in general.
An example of the above definition – Car and Petrol are connected – bear a link.
Firstly, what is the link?
- Car runs on petrol (car connecting to petrol)
- Petrol resides in the tank of a car (Petrol connecting to car)
In the first case, the 2 properties (one of a car and one of petrol) – what car runs on, of a car – and what petrol is i.e. petrol itself, of petrol – bear sameness.
In the second case, the 2 properties (one of petrol and one of a car) – where petrol resides, of petrol – and what a car is i.e.car itself, of car – bear sameness.