This is such an important principle that I’m adding it to the philosophy I’m developing (yes, I know existing philosophies already incorporate it). There should be no conflict with the interests of the individual and the interests of society, because what benefits individuals ultimately benefits the whole society.
When you say, what is good for the individual is good for society, are you pertaining to the idea of a theoretical scenerio where there is no wrong. Because the perception of what is good and bad is individual to each person. Most would agree to what is good and what is bad, but in many cases throughout history, personal gain (which would be good for the individual) ends with the pain and suffering of many because of this.