I prefer to look at things through the lenses of "harmful" and "Not harmful", "practical" and "impractical", "fair"/"unfair", ect, rather than "good" and "evil".
However, if to use the man-made terms "good" and "evil"; my personal view is that nature and reason determines the answer. Humans are at a certain stage of evolution, we are factually social species, we survive best by co-operating. Therefore, given the very social and intellectually advanced animals we are, I believe that good and evil are determined sociatally best by what is 'harmful" and "not harmful" to the individual; as a rule of nature, the individuals own liberty is best secured via the fcat that he/she is a social anaimal and part of a social species, again co-operaion is important, to best secure the individual liberties-the individual needs to logically notice that he/she is surrounded by many other "individuals" whom also want individual liberty mazimized for themsleves. As a social species, each individual best can enjoy life and have maximized liberty by respecting the indiivdual libertie sof every other individual; therefore, the individual human animal will eventually reason out that how the treat others is how others will treat them therefore the individual learns to eaither leave others be{if that individual is highly a loner} or that individual leanrs to treat others with the same dignities and helps that he/she would want for themselves.
Eventually, though this starts as a ethics born of "neccesity', because of the emotional part sof the human animals brain-real sympathy develops, compassion, respect, caring, and love feelings.
Therefore, the law sof the land are best deternimedby this; what mazimizes individual liberties w/out impeding on other individuals liberties,
On the personal level. lesser important things for the individual that do not affect others, the morality for those contexts and things is based out of "personal tastes", again keepong in mind the natural laws I mentioned-the individual does as they will, without harming individuals, as they wold not wish to be unjustly harmed themselves and they protect themselves against it by wearing the social vestments of collective ethics.
That is how so-called "good' and 'evil" are best defined.
Those human animals that don't intuituvely realize this as human ana=imals, are defective; some can be repaired via beeing taught{or 'informed'}, others can't. Breaking from this usually result sin either absurd moral absolutes based on mythologies{which usually end up in some portionof the human specie sbeing opresed and mistreated by the morally superior ones and their myths}, or in individuals whom are anaimls with defective conciences, whom go out of their way to harm, and end up eventually paying the piper{if their socal place on society is minimal; if they are an elite-they sometimes get away with it-unfortunately}
In Reason:
Irrev.Bill
