The statement kariyachi sravana ("I have heard it") is very important in the sense that hearing is more important than directly studying or perceiving. If one is expert in hearing and hears from the right source, his knowledge is immediately perfect. This process is called srauta-pantha, or the acquisition of knowledge by hearing from authorities. All Vedic knowledge is based on the principle that one must approach a bona fide spiritual master and hear from the authoritative statements of the Vedas. It is not necessary for one to be a highly polished literary man to receive knowledge; to receive perfect knowledge from a perfect person, one must be expert in hearing. This is called the descending process of deductive knowledge, or avaroha-pantha.