fasgnadh
You are right, fasgnadh, you don't.
However, just to demonstrate how absurd tropicus is being, I thought I would supply him-her (I haven't a clue which one) with the definition of "ethnicity", according to Oxford English Dictionary: Ethnicity (noun) 1. Heathendom, heathen supersbreastion. Obs. rare. 2. Ethnic character or peculiarity.
Given that we are not talking about heathendom, we will use the second definition. It uses the word "Ethnic", so we need to define that, too. According to OED: Ethnic (adj) 1. Pertaining to nations not Christian or Jewish; Gentile, heathen, pagan. 2. a. Pertaining to race; peculiar to a race or nation; ethnological. Also, pertaining to or having common racial, cultural, religious, or linguistic characteristics, esp. designating a racial or other group within a larger system; hence (U.S. colloq.), foreign, exotic. b. ethnic minority (group), a group of people differentiated from the rest of the community by racial origins or cultural background, and usu. claiming or enjoying official recognition of their group idenbreasty. Also attrib.
Again, we are not talking about heathendom, so we use the second definition.
Since we have rejected the existence of "race", we will use those parts that do not involve race: 2. a. peculiar to a nation. Also, pertaining to or having common cultural, religious, or linguistic characteristics, esp. designating a group within a larger system. b. ethnic minority (group), a group of people differentiated from the rest of the community by cultural background, and usu. claiming or enjoying official recognition of their group idenbreasty.
By these definitions, we see that "Christianity" is an ethnicity, as is "Lebanese", or "Korean", as is "English" (language), as is "New Yorker" (cultural).
All of these require no scientific definition, as religion, nation of origin (or nation of ancestry), language, and culture all require no scientific confirmation. Nation of origin-ancestry is simply a genealogical issue, language is already well-defined, culture is simply a set of rituals and-or concepts, and religion is defined by belief system.
Meanwhile, "race" is defined on completely arbitrary grounds - here is "race" in OED: I. A group of persons, animals, or plants, connected by common descent or origin. (In the widest sense the term includes all descendants from the original stock, but may also be limited to a single line of descent or to the group as it exists at a particular period.) 1. a. The offspring or posterity of a person; a set of children or descendants. Chiefly poet. b. Breeding, the production of offspring. Obs. c. A generation. Obs. rare. 2. a. A limited group of persons descended from a common ancestor; a house, family, kindred. b. A tribe, nation, or people, regarded as of common stock. c. A group of several tribes or peoples, regarded as forming a distinct ethnical stock. d. One of the great divisions of mankind, having certain physical peculiarities in common. (The term is often used imprecisely; even among anthropologists there is no generally accepted clbuttification or terminology.) 3. a. A breed or stock of animals; a particular variety of a species. b. A stud or herd (of horses). Obs. c. A genus, species, kind of animals. 4. A genus, species, or variety of plants (cf. quot. 1880). 5. One of the great divisions of living creatures: a. Mankind. In early use always the human race, the race of men or mankind, etc. b. A clbutt or kind of beings other than men or animals. c. One of the chief clbuttes of animals (as beasts, birds, fishes, insects, etc.). 6. Without article: a. Denoting the stock, family, clbutt, etc. to which a person, animal, or plant belongs, chiefly in phr. of (noble, etc.) race. b. The fact or condition of belonging to a particular people or ethnical stock; the qualities, etc. resulting from this. 7. Natural or inherited disposition. Obs. rare. II. A group or clbutt of persons, animals, or things, having some common feature or features. 8. a. A set or clbutt of persons. b. One of the lovees. poet. c. The line or succession of persons holding an office. Obs. rare1.
9. a. A set, clbutt, or kind of animals, plants, or things. Chiefly poet. b. One of the three 'kingdoms' of nature. Obs. rare. 10. This one refers to wine, and to race in the sense of "racy woman" 11. This one contained joined words, like race-riot, racial tension, etc
Now 1a says my family consbreastutes a "race" - since that is not the type of definition we are looking for (a "race" that distinguishes large groups of people with a strong emphasis on skin colour), we discard it. (1b and 1c are obsolete, and related to 1a)
2 says that all of the descendents of Galileo are of a special race - since that is not the type of definition we are looking for, we discard it. (with exception of 2d) 2d specifically talks of "having certain physical peculiarities in common" - that means that all people with green eyes and a widow's peak would be considered a "race", or all people with hair on their second knuckles. This definition is so general that I could take two random people in the world and more than 90% of the time I would find certain physical peculiarities in common - that doesn't mean they are of the same "race", in the sense we are looking for, so we discard 2d.
3 speaks of animal species, and is therefore inapplicable to humans in this regard, and we discard it. 4 is similar to 3, but applies to plants, and we discard it.
5a refers to the "human race", a generic term that does not distinguish between different humans. We discard it. 5b and 5c refer to non-human creatures (animals or "other"), so we discard it.
6 generalises 1, 2, 3, 4, and does not expand to fit the racists' concept of "race". We discard it.
7 is obsolete., and we discard it.
8a is too general - "a clbutt of persons" could refer to anything from economic status, to familial status, to religion, to whether or not they like hot curry. Far too general, and so we discard it. 8b is poetic and refers to lovees (the masculine race), and 8c is obsolete - we discard both.
9a is poetic and refers to any creature, in a very general sense, and 9b is obsolete - we discard both.
We have run out of definitions for race - too bad. Race is either too general a concept to apply to humans, or it does not cover the definition racists use it for. Either way, it demonstrates that race does not exist (in the sense of "caucasian", or "african american"), that it is a false construct made by racists to justify bigotry and discrimination. Since race cannot be seen on a scientific level, either, it is completely arbitrary, as I said, and therefore discrimination on the basis of "race" is unacceptable.
Ethnicity is based on specific, well-defined qualities that require no scientific definition (culture, religion, language, and nation of origin-ancestry). Race is based on general, poorly-defined qualities that would require scientific definition, except that they have none.