Activity
Activity takes place through the body, the organ of speech, and the mind. These three are called yogas.
Yoga means - activity, restlessness.
Factors of Pleasure and Pain
The four influxes dull awareness. Therefore they are the causes of sorrow. Activity in itself is not the cause of pleasure and pain. Only when it is inclined towards perversity, etc., does it become a factor of sorrow. The entry of karmic particles takes place through it; it is thus an influx. The karmic particles cling to various parts of the soul. That constitutes the bondage. After being bound, the karmic particles remain active according to their strength. Then, after being consummated, they enter the state of realization and ultimately are dissociated. In the time of realization of karma, a man experiences pain or pleasure.
In the language of spirituality, influxes are the causes of pleasure and pain. The feeling produced by the realization of karma constitutes suffering or happiness. With the dissociation of karman, the doors of both happiness and suffering are shut. In that state one experiences spiritual bliss. As long as the process and activity of an influx continues, a man lives in the cycle of suffering and material pleasure; he cannot experience spontaneous, natural joy. Each soul is endowed with endless knowledge, ever-lasting intuition, unlimited joy and limitless energy. But because of the influxes, this eternal quartet does not manifest itself. During the operation of an influx, knowledge and intuition are shadowed, happiness distorted and energy lie dormant. The defilement of the soul is not natural. It is all created by the influx. On this basis, souls are divided into two categories-bound and free. A soul afflicted by an influx is bound, and that without an influx is free.
As long as the instincts and actions created by the influx exist, it is not possible to directly experience the fundamental nature of the soul. Only through the purity of the mind, concentration, penance, the practice of the bhavana of rivalry, or the practice of meditation take place. When the force of the influx is neutralized, can one realize the true nature of the soul.
In brief, the quintessence of Jain phlosophy is - that the influx is the cause of sorrow, and the subjugation of passions leads to spontaneous joy.