In this article I propose the classification of the evolutionary stages that a scientific discipline evolves through and the type of scientists that are the most productive at each stage. I believe that each scientific discipline evolves sequentially through four stages. Scientists at stage one introduce new objects and phenomena as subject matter for a new scientific discipline. To do this they have to introduce a new language adequately describing the subject matter. At stage two, scientists develop a toolbox of methods and techniques for the new discipline. Owing to this advancement in methodology, the spectrum of objects and phenomena that fall into the realm of the new science are further understood at this stage. Most of the specific knowledge is generated at the third stage, at which the highest number of original research publications is generated. The majority of third-stage investigation is based on the initial application of new research methods to objects and/or phenomena. The purpose of the fourth stage is to maintain and pass on scientific knowledge generated during the first three stages. Groundbreaking new discoveries are not made at this stage. However, new ways to present scientific information are generated, and crucial revisions are often made of the role of the discipline within the constantly evolving scientific environment. The very nature of each stage determines the optimal psychological type and modus operandi of the scientist operating within it. Thus, it is not only the talent and devotion of scientists that determines whether they are capable of contributing substantially but, rather, whether they have the 'right type' of talent for the chosen scientific discipline at that time. Understanding the four different evolutionary stages of a scientific discipline might be instrumental for many scientists in optimizing their career path, in addition to being useful in assembling scientific teams, precluding conflicts and maximizing productivity. The proposed model of scientific evolution might also be instrumental for society in organizing and managing the scientific process. No public policy aimed at stimulating the scientific process can be equally beneficial for all four stages. Attempts to apply the same criteria to scientists working on scientific disciplines at different stages of their scientific evolution would be stimulating for one and detrimental for another. In addition, researchers operating at a certain stage of scientific evolution might not possess the mindset adequate to evaluate and stimulate a discipline that is at a different evolutionary stage. This could be the reason for suboptimal implementation of otherwise well-conceived scientific policies.