Padartha Vijnan is a subject that deals with the basic principles of Ayurveda. Generally, students are taught subjects like Biology, Physics, Chemistry from their primary school level. As they go higher up in their studies they keep learning more and more about each one of these subjects.
In our education system, we do not have any subject that deals with principles of Ayurveda. So any student joining Ayurvedic course finds all the subjects alien to him or her. Do not get upset at this. You can learn the basic principles of Ayurveda with a good grasp of this subject, Padartha Vijnan.
All the topics covered in Padartha Vijnan will help you through out your degree course in learning all other subjects in Ayurveda like Anatomy, Physiology, Pathology, Diagnosis and Treatment. So, develop interest in the subject and learn it thoroughly. This subject to Ayurveda is like an alphabet to any language.