In Diana's critique, she finds one quote by Ayn Rand that pertains to this subject:
"Productive work is the central purpose of a rational man’s life, the central value that integrates and determines the hierarchy of all his other values. Reason is the source, the precondition of his productive work—pride is the result."She then notes that this definition of central purpose should simply be productive work, that an integrating theme to productive work is not necessary, just that productive work in and of itself should be central. She doesn't see an integrating theme or a singular passion as necessary for happiness. While I agree with much of what she says, there is second quote on central purpose that drives my understanding of the idea, which seems to differ from her take. The quote comes from her Playboy interview:
"A central purpose serves to integrate all the other concerns of a man’s life. It establishes the hierarchy, the relative importance, of his values, it saves him from pointless inner conflicts, it permits him to enjoy life on a wide scale and to carry that enjoyment into any area open to his mind; whereas a man without a purpose is lost in chaos. He does not know what his values are. He does not know how to judge. He cannot tell what is or is not important to him, and, therefore, he drifts helplessly at the mercy of any chance stimulus or any whim of the moment. He can enjoy nothing. He spends his life searching for some value which he will never find . . . ." [emphasis mine]
The latter quote does suggest an integrating function to productive work is ideal. She says "A central purpose..." suggesting that their is a singular purpose that integrates everything else. This focused purpose to the type of work you do helps create a hierarchy of values and enables you to enjoy life more fully.
I have written about my search for an integrating purpose to my life and the enjoyment I have received from the resulting career. It has helped me to resolve inner conflicts and define my hierarchy of values. For me, defining a CPL is not a moral issue, but a useful tool for actualizing my full potential. I can and do have many interests. I could potentially pursue a wide variety of projects and enjoy them all. But when I focus on an integrating idea, when I search for a value-dense purpose, I find greater enjoyment in life in general.
Are you immoral without a CPL? No, but you're missing out. I see a well defined CPL as a tool for achieving a satisfying and enriching career. It is a tool that helps identify our hierarchy of values. You shouldn't beat yourself up if you don't have one, but spending some time reflecting on your passions and your purpose can help you to achieve more.
Is a CPL obvious? For some it is, for many it is not. I took me until I was 27 until I discovered my CPL implicitly and until 33 before I could explicitly write it down. It involved identifying and integrating all of the things that had happened in my life and all the jobs I had loved and hated, until I finally saw how they all related. And it was hard work! But I know of other people who knew from an early age what they wanted to do (like Ayn Rand). For them it was obvious.
Can multiple major purposes exist? Absolutely. I know of people that have multiple interests and live happy lives. Is it the best way to live? I liken it to a business that has multiple lines of business. The greater the similarities between those lines of business, the greater the synergies that will emerge, which can lead to greater success. The business owners may indulge in multiple lines of business that have no relationship to one another and enjoy each thoroughly. They can even create a positive cash-flow in each line of business. But how easy would it be to run such a business? If a hierarchy of values is not established, which line of business would get what resources? Which would get the most attention, money, time, or effort? With a hierarchy of values, something must be at the top. That top value is your central purpose. The more projects and activities that support that highest value, the less conflict and confusion you'll have. That's not to say you can't enjoy hobbies, your family, your friends, or your own body. But what is central? What is most important? There is a bunch I can say about how other values fit in with the CPL, but I'll save that for another post.
Could you be happy without defining a CPL? Yes. But the better you can find an integrating purpose, the less inner conflicts you will experience and the better equipped you will be for directing your life. Again, it's about degrees of enjoyment and does not preclude other values that you can enjoy as well.
Can a CPL change? Yes, but if it changes often or deeply then it probably was not well defined. I remember when I was much younger, interviewing for a job in web development. The interviewer asked how my previous employment in tutoring and teaching related to web development. She wanted to be sure that web development wasn't some passing whim. That I had some integrating purpose to my life. I immediately saw the connection, in both cases, I wanted to facilitate the transfer of knowledge. In one case through face-to-face classroom instruction and in the other case through electronic medium. The connection between the two jobs was not vast to me, because I was already starting to identify and integrate my passions. The interviewer was very impressed with my answer and eventually offered me the job.
Can parenting be a CPL? As a nanny, yes. As a stay at home parent who homeschool, maybe, if it is something that consumes the parent's productive efforts. And even then, the purpose shifts from parenting to education. Otherwise, no. A mom who takes a 5 year break from her career to raise her kids, while doing something extremely commendable, is not pursing a central purpose, but rather taking a break from it. Raising children can become the highest value temporarily, until they are old enough to care for themselves. But from what I've seen, moms (not the homeschooling variety) tend to be far happier if they can return to working on their CPL after that break. Any women out there want to correct me on this observation???
Given my understanding of CPL and its value to our lives, I would recommend people attempt to define and live by one. To me, this is your highest value and the most important concern. If this value is not carefully defined, it is easy to slip into careers you either don't enjoy or feel indifferent about. And that, to me is a travesty.