In their attempt to find out the answer for the pain and suffering etc., of the human beings, the great sages and the visionaries of Bharathavarsha found the answers in six different ways which are known as Shad Darshanas or the six systems of philosophy.
Darshana means seeing the reality of things. In Darshana, everything is known or perceived with a right vision. In Darshana, there is discernment; everything is perceived with proper discrimination with right distinctions. With a keenness and good judgment, the reality of things is seen.
Today, the term philosophy has become a narrow term because it is generally understood as a subject of speculation. Though philosophy means the love of wisdom, it has been reduced to a very narrow study and practice by the people, who are not keen on knowing the truth.
As the people are different, so are the different forms of teaching and practice. Every individual must follow that path for which he or she is fit and competent.
Today, the materialism is advocated too much by a section of people of the society. They are giving too much emphasis on the external world rather than the spiritual concerns. Their ideas, thoughts, feelings, minds are fixed on the acquisition of the material wealth. There is too much devotion to develop a huge wealth and a vast material world and also too much of an interest to adopt and invest in the materialistic values.
Shad Darshanas: Nyaya, Vaisheshika, Samkhya, Yoga, Mimamsa, Purva Mimamsa and Uttara Mimamsa or Vedanta
Maharshi Pathanjali is the first to codify yoga and its practice. In his Yoga Sutras, Maharshi Pathanjali explains the discipline of Yoga in the form of motivation or incentive to study yoga. Maharshi Pathanjali never orders or commands to practice yoga in any particular way but narrates what yoga is and what happens when yoga is practised. In his Darshana, known as Yoga Darshana Maharshi Pathanjali defines yoga and informs what are the results of practising yoga. You can study both the theoretical and the practical aspects of yoga in Yoga Darshana.
Here is an Interesting story about citta: Krishna-Karna Samvad
This citta is fickle. It gets loaded with thoughts within no time. Then you are misguided and you do the wrong things. So, control this citta.