The 25th Step: Gratitude
If rain were to fall continuously and there was no evaporation to produce clouds to make rain to fall back to earth, sooner or later there would be a drought, causing the earth to turn into a desert. Similarly, we need to rely on each other's support and exchange services and goods with each other.
The causes of living happily and peacefully with allbeings are:
1) Upakara, which means supporting others with goodwill.
2) Patikara, which means to give back to our benefactor's kindness. For instance, a son expresses his gratitude to his parents in their old age, or a student who pays respect to his teacher.
These two causes of good living can help foster progress in the world. On the contrary, if a son is ungrateful to his old parents and abandons them, or a student does not pay respect to his teacher, the world would be unfavorable.
Thus, gratefulness makes the world survives. Returning a benefactor's kindness by gratefully doing favors is known as "Katavedi" which is conducive to "katannu" or honoring the person who has done the favor by being grateful.