Constituent and Composite Entities (BPC)
| Broad Physical Categories (BPC) | Definition |
|---|---|
| 5. Relationship | A property of an entity where a property or set of properties of that entity are conditioned by the properties of another entity. |
| 6. Constituent Entity | An entity, being in a relationship or set of relationships with another entity or set of entities, constituting a composite entity. |
| 6. Composite Entity | An entity having particular properties conditioned by a set of constituent entities and the relationships between them. |
These two terms, constituent entity and composite entity, come about as a result of relationships. Both categories mutually condition one other, so they are put side by side in the list at the same level of the hierarchy.
A wicker fence is a composite entity with many interwoven sticks as contiuents. Each stick has its own properties—size, strength, color, etc. But when we bring these sticks together, the fence as a whole has properties that the individual sticks do not. The fence can now impede the progress of animals, while individual sticks cannot.
Once a whole has properties of its own, then that whole is a single entity.
Furthermore, composite entities relate to other external entities as a whole; the way composite entities come into relationships with other external entities is not based on the properties of the contituent parts but based on the properties of the fence as a whole composite entity. This fact has two aspects:
(1) Properties of the whole are conditioned by other entities; when a composite entity is in a relationship with an exterior entity, the properties of the composite entity as a whole are altered by the relationship. When an animal presses against the fence, it bends the whole fence, bending all the sticks, not just one of them, because the sticks are interwoven.
And, (2) Properties of the whole condition other entities; when a composite entity is in a relationship with an exterior entity, the properties of the composite entity, not its constituents separately, condition the properties of exterior entities. When an animal presses against the fence, the animal experiences a force that is dependent on the strength of the fence as a whole, not the strength of the individual parts.
This perspective is indispensable in the formation of the atomic theory of matter. When hydrogen and oxygen gas are exploded together, they form water. Just like the fence, the composite water molecule has properties that the constituents do not. It's a liquid at room temperature, while hydrogen and oxygen are gases. Just like the fence, it comes into relationships with exterior entities as a whole: when a person drinks it, it will quench his thirst, acting on the human body in the way water does, not in the way hydrogen or oxygen do on their own.
Chemists infer the relationship between oxygen and hydrogen. They could not see the relationship, after the explosion i.e. after the water had formed, but they could see that when hydrogen and oxygen come together, they form a completely new entity with completely new characteristics. As a result, they could infer the existence of an invisible relationship between hydrogen and oxygen. Since physicists knew that there was such a relationship, they were able to identify that relationship later as covalent bonding, the sharing of electrons.