The library has become the house of books and a conducive place for people who love to read. The library's collection is growing in terms of both printed and non-printed materials. Ergo, as it grows, it needs someone who can take care of it and provide it to the library user, who is the librarian. So, what is a librarian? The librarian is a steward of books and other resources, and manages the library and users. The librarian is entitled to the function of librarian. Librarianship is a profession that provides knowledge about organizing books and serving library users. According to the Information School of University of Washington (2019), librarianship is concerned with the collection, organization, preservation, and dissemination of information by librarians who assist and locate resources to meet individual needs users. To become a librarian, ethics are important and must be paid attention to. It's a challenge to meet other people with different needs and wants. Satisfaction with the service provided to users is one of the librarian's objectives. This leads to a pleasant environment and happy success. As St. Thomas Aquinas said, every human being must nourish himself by choosing what to do and achieve ultimate happiness. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essaySt. Thomas Aquinas is a great philosopher and angelic doctor, who was treated badly by his friends in his class. He was bullied; however, in his sacred works there was no trace of criticism or obscurity about his life (O'Connor, 1967). Having become the patron saint of academic institutions where theology and philosophy are taught, he wanted to apply his knowledge not only within the confines of institutions, but also in the daily and practical lives of people (Elders, 2006). He believes that people must find and identify their purpose before doing something (Robinson, 2015). Saint Thomas commented on Aristotle's text, The Nicomachean Ethics, saying that it is a valuable ethical treatise. Aristotle's Nicomachean Ethics is concerned with the nature of a person being ultimately good and the examination of human actions as to their main ultimate goal which has a characteristic of complete, final, self-sufficient and continuous which aims at ultimate happiness . However, St. Thomas Aquinas states that ultimate happiness is not possible when a person is alive and remains imperfect, and that ultimate happiness can only be found in heaven or in bliss with God. For this reason, we not only need virtues, but also God who dictates our life to make our nature perfect and participate in divine bliss. Ethics comes from the Greek word “ethos” and a discipline of philosophy dealing with good and evil that has moral value. duty and obligation. This is how people make decisions and choose their actions. It has a branch of professional ethics that concerns the moral rules and behavior of the professional that helps him or her choose what to do when faced with problems at work that raise moral concerns. Librarians have professional responsibilities in providing effective and efficient library services which should be guided by ethics and a set of values. The aim of the librarian is to provide the good service and information to the users because he needs ethical conduct that satisfies the users. Another advantage of having users in the library isto give them good morale. It is essential to have a good attitude towards the users, otherwise it could be a dead library and the users would tend to have a bad image of the library and the librarian. Librarians play an important role in people's lives as they have the responsibility of serving users' needs and information. Librarians must instill professional ethics. It is important to have professional values ​​and to be followed by members in order to know how to act well and avoid problems. In agreement with the International Federation of Library Associations and Institutions (IFLA) (2012), one of the key elements of a profession is to have an effective code of conduct and to develop professional status, which codes imply on “how to be professional”: the code “essentially instrumentalizes a code of ethics, clarifying the applications of ethical concepts in daily professional practice” (Freeman, 1996). The code of ethics is important to librarians because they often face ethical dilemmas in which they may violate professional ethics. In Phillips et al. (2018) study “Awareness and Perception of Ethical Issues in Library Service Delivery by Librarians of Ibadan Polytechnic, Nigeria: A Phenomenographic Study,” according to Onoyeyan et al. (2014) defined ethical dilemma as a situation in which there is a conflict between principles and a choice of action that must be determined, and cited by Stueart and Moran (2002) listed some ethical dilemmas librarians might be faced with. faced such as: using an employer's property for personal purposes, accepting fringe benefits, influence peddling, disclosing confidential information, working outside or undeclared and having conflicts of interest after job. Phillips et al. (2018) explains that these dilemmas could be illustrated in all sorts of ways: “If a librarian converts the library's information resources to private use. Also if a librarian takes home several books from the library for the personal use of his children or wards. An acquisitions librarian may also be faced with the decision of whether or not to accept benefits, particularly from vendors and publishers, in exchange for continued support that is hoped to be unwavering whatever the circumstances. It is also possible that a reference librarian could fall into a situation of influence peddling if they allow their romantic interest in a patron who is not being referred to come between themselves and the provision of services. A circulation librarian could be forced to divulge vital private information about their patron in exchange for money or monetary reward. A librarian may also find themselves in a moonlighting situation in which they offer their professional expertise outside the library during their official hours for compensation. A post-employment conflict of interest could occur if a librarian, after resigning or retiring from the library, now uses the skills and abilities he or she has acquired to obstruct his former library. »According to Shawn Floyd in his article “Thomas Aquinas: Moral Philosophy”, the nature of human action is rational, as Saint Thomas Aquinas explains in the Summa theologiae, involving two powers: cognitive and appetitive; cognitive power is the intellect that allows a human to know, understand and hold good, while appetitive power is the act of the will described by Saint Thomas Aquinas as a native desire of thewell understood. Human beings are the ultimate crowning glory of God's creation in the universe who possesses God-given dignity. These ethical dilemmas in the library would mean nothing good for ultimate happiness and truth. St. Thomas Aquinas believes that the supreme truth is God and the supreme goodness is God, so the ultimate goal is to know and love God. (Wishloff, 2016). Saint Thomas Aquinas emphasizes the nature of ethics: “To live our lives as we should, knowledge of the end is necessary”; however, this knowledge should form the basis of good actions (Elders, 2006). Therefore, librarians must act correctly and separate themselves from wrongdoing. A person's motives have identical actions which can be good or bad from the point of view of Saint Thomas Aquinas. His view on the ethical principle has an effect of natural moral knowledge, according to which everyone has an innate knowledge of the natural law which is synderesis, therefore this only appears in reason and not in dispositions (Robinson , 2015). Synderesis sometimes experiences consciousness which is an operational practical intelligence; However, according to Saint Thomas Aquinas, we must follow our conscience which guides us what is the moral thing to do and those who are against it are against the values ​​of truth and reason. Andrew Robinson (2015) discussed the four main virtues according to St. Thomas Aquinas: “Prudentia, the act of introducing moral reasoning into all decisions and placing it ahead of irrational desires and ego promotion. Reason, rather than passion, is at the heart of moral decisions; Justice, a disposition to give others what they are entitled to or entitled to; Courage (strength), a willingness to hold back one's fears in order to act correctly; Temperantia, the moderation of desires, particularly sexual, in accordance with their “proper role”. The IFLA Code of Professional Ethics for Librarians aims to make all librarians aware of their ethical commitment to their profession. The function of the code is to encourage reflection on the principles on which librarians and other information workers can develop policies and manage dilemmas; improve professional self-awareness; and ensure transparency towards users and society in general. One of the many national codes of ethics that has caught the attention of librarians is the Code of Ethics of the Thai Library Association. The Thai Library Association declared its code of ethics in 1977, which supports and promotes librarianship and library education in Thailand and protects the welfare of library staff. The TLA Code of Ethics is structured around five axes: Ethics towards users: perpetuate the good relationship between the library and its users; Ethics towards the profession: ensuring responsibility for the development of the profession and promoting excellence among library professionals; Ethics towards colleagues: strengthening cooperation between library professionals and increasing good relations with colleagues and other members of the profession; Ethics towards the organization: defend and respect the library as an integral part of the organization or institution; and Ethics towards society: affirming the status and role of libraries in providing information for the advancement of society. This describes the behaviors that the librarian must adopt when applying in order to provide quality service. It is included in one of the three branches of ethics, as distinguished by Aristotle, as a task of man in political society and by its mainvirtues, and Saint Thomas Aquinas recognized that human beings have their various tasks, obligations and rights. Furthermore, ethics implies that all human beings aim for the good and that all our choices and actions should be made when it is right for us. The American Library Association's core values ​​also encourage librarians to do good deeds. It aims to guide library professionals in the values ​​and development of their profession by refining the association's numerous statements including access, confidentiality/privacy, democracy, diversity, education and lifelong learning, intellectual freedom, preservation, public good, professionalism, service, social responsibility and sustainability. A problem has arisen for the librarian and one of them is the lack of morale of the librarians in the library. In Kaetrena Davis Kendrick's (2017) article, "The Low Moral Experience of Academic Librarians: A Phenomenological Study," defines low morale as the degree to which an employee experiences negative feelings toward their work environment and its organizational culture. Kendrick (2017) provided LIS articles on workplace bullying, incivility, toxicity, and burnout, as well as associate concepts and processes that she examined, which on the Workplace website Bullying Institutes consider that the main initiators of workplace bullying are bosses. It was also discussed that some librarians suffer from burnout which includes health problems; however, there were also librarians who were not burned out because they were engaged in their work and managing their expectations (Kendrick, 2017). According to Kendrick's (2017) study, some librarians experience abuse; “Emotional abuse, including manipulation, intimidation, thwarting, targeting, invasion of privacy, or micromanagement; verbal/written violence, including lying, public humiliation, shouting/screaming, castigation, contempt, fleeting or unfounded complaints, misinformation or denunciation. Verbal abuse also included the use of oral communication to circumvent formal reprimand processes in an attempt to cover up verbal abuse and associated system abuse; system abuse, including system rigging, cronyism, steamrolling, or violation of human resources or workplace policies and procedures; negligence, including laissez-faire or ambivalent library or campus leadership/administration, lack of advocacy, capricious decision-making, or ineffective communication. For St. Thomas Aquinas, “lying is bad” because it violates the purpose of language and produces inner conflicts; and criticism would mean an unfair opponent, but for others it seems that it helps them to know their wrongs and to right them. Doing wrongdoing is a big no no to achieving ultimate happiness. God created each individual with the character of good deeds and these will not be fulfilled by anyone. Anyone can act accordingly since God also created and foresees negativity in the world. These things can separate that from truth and ultimate happiness. The task of the human being is to unite with the good, and ethics will not aim for a perfect being but will hold and connect with the good as its end (Elders, 2006). God created library knowledge so that everyone would know how to value books and librarians were entrusted to take care of them because they have the capacity and ability to manage the house of books. These things.