Ethical concepts

In the original position, one is asked to consider which principles they would select for the basic structure of society, but they must select as if they had no knowledge ahead of time what position they would end up having in that society. This choice is made from behind a "veil of ignorance", which prevents them from knowing their ethnicity, social status, gender, and (crucially in Rawls's formulation) their or anyone else's ideas of how to lead a good life. Ideally, this would force participants to select principles impartially and rationally.  

Morals and virtues are both important aspects of ethical behavior, but they differ in their focus and application. Morals are principles or beliefs that guide a person's behavior and decision-making, often based on societal norms or religious teachings. Virtues, on the other hand, are qualities or traits that are considered to be morally good and desirable, such as honesty, compassion, and integrity. While morals provide a framework for ethical behavior, virtues are the qualities that individuals strive to embody in order to lead a virtuous life. In essence, morals dictate what is right or wrong, while virtues reflect the character and values of a person.

The purpose of this line of questioning is to establish consistency in one's moral framework. Simply put, the process starts with the following question; what is the morally relevant trait that an animal has and a human lacks that if a human had that trait it would make it ok to exploit and slaughter that human for food (or any natural language variation of it). With this question we're seeking to find the morally relevant trait difference between a human and an animal that make it ok to exploit and kill animals but not humans.

Statements that are based on facts are arguments, not mere opinions. These statements can colloquially be called opinions, but there's a difference between an opinion that is based on reliable evidence and opinion that is based on poor evidence or no evidence. If opinions are based on reliable evidence, then they carry more weight than opinions are not, so dismissal of every statement as "opinion" is lacking in nuance, and is a category error.