When Sertillanges talks about the intellectual vocation, he is speaking about vocation as a call from God that involves our entire life, but doesn't exclude other vocational aspects of our life - marriage, apostolic celibacy, priesthood, etc. The intellectual vocation could be synonymous with our professional vocation as would probably be the case with the prototypical intellectual vocation - Academic. On the other hand, from the perspective of time, it could occupy much less time than our professional vocation, but, in the order of love, it should be higher. And, like other vocations, this one requires discernment, a topic we will discuss in the second part of this post.
The all encompassing nature of the intellectual vocation is dear to Sertillanges, who undoubtedly titled his book The Intellectual Life to emphasize this point. Of course, we are not always reading, researching or writing. But, taking best advantage of the hours available for this beautiful task requires, among other things, recollection and solitude. Treasures that cannot be summoned after tooling around Linkedin for an hour. This excludes false ideas of the intellectual vocation, namely, all intellectual workers should try to live it, or that all can. Or, that the intellectual life can be lived without production. Those who aim at these goals can benefit from parts of this book, but the whole is directed to those with a more substantial call.
This call requires that the mission of the intellectual be more elevated than most of us consider it to be. In the body of Christ, each member is necessary, and the intellectual is especially important because he brings understanding to the rest of the body. And, this understanding "directs" the body as our mind directs the rest of our limbs. How does the intellectual bring light to others? In broad terms, he explains fundamental truths in contemporary language and/or explains contemporary events in light of fundamental truths.
The intellectual has the vocation to respond to the cry for meaning that rises up from all peoples. "If you are designated as a light bearer, do not go and hide under the bushel the gleam, or the flame, that is expected from you in the house of the Father of all."** The mind provides the justification for action: the ratio for any behavior, but modern man's reasons need to be explained in ways that he understands not in archaic formulas - true though they may be. An intellectual will provide these reasons, suited to the times, but not perverted by them.
This mission may be difficult to see for us who value practical knowledge above its speculative superior. Give me what works, what pays! But, the foundations of the most speculative science, metaphysics, are imminently practical. What could be done in the world of engineering and technology without the ubiquitous, yet quiet principle of non-contradiction? Each field has their analogous principles that need to be elucidated and explained. Better explaining these foundations, "impractical" as they may appear, is necessary for practical purposes and is a participation in the Truth.
*quotes from "The Intellectual Vocation," section I
**This quote from Sertillanges makes reference to today's Gospel, by the way.