is chemical entity intended to cover macroscopic entities like organism

[cmungall]

SIO splits material entity into chemical entity and specialized chemical entity

all kinds of large objects like humans, telephones are classified under chemical entity, as are waves:

According to #20 this is intentional. This makes sense from a reductionist viewpoint, we are all made of chemicals, hence chemical entities. But the problem here is that

1. this is not consistent with the definition of chemical entity "A chemical entity is a material entity that pertains to chemistry."
2. it poses the question of what is the difference between a material entity and a chemical entity. Do we need both? Are thre MEs that are not CEs?

To partially answer 2, ME has another subclass

but things here also seem like chemical entities...

I see a few solutions:

1. respect the current definition of chemical entity (pertaining to chemistry, which I interpret roughly to be something we can ascribe chemical properties such as charge to) and create a new home for larger objects like telephones, sibling to chemical entity
2. keep the current structure except collapse CE, ME, SCE, retaining ME as the name
3. keep the current structure and somehow dive CE and SCE new definitions that both reflects their subclasses and tells us how they differ from MEs

[micheldumontier]

@cmungall thanks posting this issue, and apologies that it slipped past me for 2 years! i think you raise very good points worthy of some further discussion.

first, on material entity, namely that it is an object that has mass, which is different from other objects such as information content entities (somewhat abstract and can exist in some way on zero or more material entities) and spatial regions (parts of the physical universe that may or may not contain other (material) objects).

the definition for chemical entity "... which pertains to chemistry" is intentionally vague, and meant to align with that of chebi https://www.ebi.ac.uk/chebi/searchId.do?chebiId=24431 , something of a grouping function of all kinds of mereologically distinct things (e.g. atoms, bonds, molecules, compounds/substances)

previous editions of SIO did indeed put substances (e..g telephones) as a sibling to chemical entity (which was more focused on the arrangement of atoms and bonds). but this was sometimes challenging to identify the boundary between them, especially with smaller objects.

if we were to go back, we'd have to make some terminological changes to make it a bit more clear, or as you suggest, we remove some of these categories because they aren't worth the distinction.

@cmungall what would you prefer to do?