Quantitative methodology has been the predominent methodology utilized in research in nursing. However since the 1970s qualitative methodology has also emerged as a useful methodology and has been utilized by many researchers. But in the use of this methodology, the philosophical, epistemelogical, and theoretical backgrounds have been neglected by many researchers. This paper reports a review of the literature on methodologies, quanitative and qualitative, used in nursing, and makes suggestions for future research directions. It explains why qualitative methodology has emerged as as effective methodology in nursing and discusses how the qualitative methodology differs from the quanitative one. A comparison of the two is made based on perspectives of humane being and human behavior as well as the development of nursing science. This paper also presents several views on change in nursing science, since viewpoint not only influences the determination of the current stage of nursing science but also the shaping of the future directions of nursing science and research. Scientific revolution by Kuhn, the evolutionary perspective by Toulmin, the transition of research tradition by Laudan. and convolutionary processes are presented. However, this paper indicates that it is too early to adopt these points of view, because the history of nursing science is too short. It suggests that nursing needs pluralism in philosophy, paradigms and theory, as well as in methodology. Although we experience paradoxes in adopting different perspectives in nursing, it is wise for us to continue to include a variety of viewpoints including those to which we are not accustomed, such as qualitative methodology, since we are not yet able to decide what is best for the development of nursing science.