The introductory chapter of Bhagavad Gita Home Study by Swami Dayananda contains a detailed discussion of Pursartha. Swamiji begins with the definition of purushartha also in his Advaita Vedanta book.
The topic of Purusartha provides an excellent starting point for a vedanta student.
Let us follow a step by step procedure to define Purusartha. Some of you may not be aware that we use this term in every puja.
Step 1: We invoke the grace of Isvara by chanting along with Sri Swami Omkarananda, a sample MP3 which is provided in the following link.
Step 2: We pray to Ganesa to remove all obstacles.
Step 3: Then comes sankalpa. Sankalpa is the statement of purpose of this puja.
We shall concentrate on the portion where we say "dharma artha kama moksha cathur vida phala purushartha sidyartham". (The sankalpa can also say "Sri paramesvara prityartham". We will not discuss this method right now)
We seek Isvara's blessing in our seeking of four goals - kama, artha, dharma and moksha. This set of four human goals is called पुरुषार्थ: purushartha.
(1) kama: Enjoyment. I want to be happy by enjoying the objects of my desire. This goal is common to both humans and animals.
(2) artha: Security. I want to safely guard my possessions so that I can continue to enjoy them. This goal is common to both humans and animals.
(3) dharma: Ethics. My seeking of kama and artha is ethical. I do not perform any actions which is adharma. My actions confirm to dharma, so that I can go to heaven. A non-religious person is ethical, because it is a decent human tendency.
(4) moksa: Moksham. I am told that there is something called moksa, which is a fantastic goal to reach. I add moska in my "To Do" list as a last priority. This goal is unique only to humans.
While the first three goals are easy to understand, moksa needs a good analysis as a separate topic.
