I agree that 'morality' lacks 'existence' in the same sense that 'straight line' lacks existence. I understand that this is your main point and I agree: no one here will be capable of producing a 'real morality' for you.
Dang!
But 'objective' does not mean 'to have existence' where 'existence' is in the same sense as 'carbon' or 'light' or 'stars'. 'Objective' means 'not influenced by personal feelings or opinions in considering and representing facts'.
'To be objective' is a way for a human to consider a question, and has the qualities you mention. However, it's not possible for a moral rule, a maths rule, a physics rule, a rule for line-dancing, to possess such a quality. A human applying such a rule might proceed 'with objectivity' but the rule will remain a rule, that's to say a concept, not a thing with objective existence, not a thing existing in external ('objective') reality independently of the concept of it.
For example, when a mathematician proves that 'the square root of 2 is irrational', he arrives at an objective 'fact' by proof, not by subjective 'opinion' based on how he feels about it.
No he doesn't. Instead he arrives at a conclusion validly derived in accordance with the rules of the relevant branch of maths. The rules, and the processes, and the mathematical objects they apply to, are
all conceptual, and the objects, exactly like our Euclidean straight line, have no counterpart in reality.
'Imaginary' does not mean 'subjective'. If that were the case, we would throw out quite a bit of thinking (including the rules of logic).
Then where I've said 'exist only in imagination', please read, 'exist only in mentation'.
Being a concept existing inside minds does not automatically make a concept subjective. That way of thinking is absurd: it turns the very idea of something being 'objective' into a subjective matter; under those rules there is no such thing as objective reality.
Not quite. The question is whether the concept refers to something with objective existence (eg 'this chair'), in which case it's about reality, or not (eg 'a chair'), in which case it's about, and only about, things in mentation.
Otherwise, we would be saying the equivalent of pieces of paper with bunches of letters written on them are 'brain-like' things that hold concepts (which sounds like a bunch of nonsense to me)... unless you think physics textbooks actually spend time thinking...
No, a complete definition of a 'brain-like thing' will depend on the conclusions we reach in the course of brain research, but these already show that the very great majority of brain activity is done by the nonconscious brain, . You may be aware of the experiments some years ago which showed that the brain had already made a particular decision up to ten seconds before the conscious brain was aware of the decision. Or more simply, ponder where the words you speak or type 'are', up to the millisecond before you say or type them ─ only very rarely in the conscious brain.
More relevant is the fact that morality applies primarily to thinking beings such as human beings. What does morality even mean when there is nothing to which it applies?
First, morality is a quality that may be attributed to a roughly-defined set of animal, usually human, attitudes about the relationship of the individual to others, and the decisions and behaviors that result from them. These have their sources in genetic tendencies, such as child nurture and protection, dislike of the one who harms, fairness and reciprocity, respect for authority, loyalty to the group, and a sense of virtue or self-worth through self-denial, which are present in all societies. Or they may derive from particular customs, such as whether a wedding entails a dowry, a bride-price or neither, how to hold a knife and fork, whether and if so when you may spit or fart, and so on. And then each human has a conscience, the sense / conviction that certain rules of behavior have universal application, and aren't simply opinions (though the list of such rules will vary with the individual).
So morality ranges from largely fixed, like child nurture, to arbitrary (blackballed for wearing inappropriate socks, the moral judgment 'not a person we want to associate with').
(The Ten Commandments are an egregious example of arbitrary selection and crap draftsmanship. Don't get me started.)
When the state of Indiana tried to pass a
law squaring the circle, it wouldn't have made squaring the circle a fact!
If I had to do that, I'd start by offering a replacement definition of a circle, so that it fitted my maths and not Euclid's.
The 'objective test' that you are using is a test for 'real existence' and not a test for 'objectivity'.
As I said, I don't agree that 'objectivity' can be used here in the sense you propose. (And I continue to equate 'objective existence' with 'real existence', in contrast to 'existence solely in mentation'.)