The phrase seems to be speaking of a universal need by all men (and women, of course) for something vaguely called spiritual.
"The modern western worldview is dominated by the materialist values of science. According to Huston Smith, Ph.D., this withdrawal of emphasis from human values--and from essential elements such as meaning, quality and purpose--has led to widespread alienation and social discontent."
Now, having quoted Mr. Smith ... I hope that you can see the value in what is 'meant' rather than interpret it to mean a whole disregard for science. I came upon a certain understanding back in grad school when I was taking a life-stage development class (psych) and the brief premise is that within each decade of our lives
we tend towards ... figuring out the same things.. such as relationships, career, family, etc.. and spiritual ..
"(James)Fowler's Theory of Faith Development
The adult stages in Fowler's theory typically include stages three through six. The earlier stages generally follow normal progressive development, and the various stages of faith are neither achievements, nor progressive steps to salvation, but simply degrees that one's faith goes through as it develops. The following is a short description of each of these stages:
Stage 3. Synthetic-conventional: In this stage, a person knows why he/she believes. One pulls together various parts of faith and tends to conform to the majority, and people are rewarded or punished for following rules laid down by the proper authority (the church or Bible). Views at this stage are often stereotyped.
Stage 4. Individuative-reflective: There is a relocation of authority within the self, along with a critical reflection of one's beliefs. Faith becomes uniquely one's own. In addition, there is usually a struggle to grow and understand.
Stage 5. Conjunctive: Individuals realize the paradoxes in faith, and learn to live with their faith and their questions. This stage involves a dynamic, trusting relationship with Source/God/Universal Spirit etc....
Stage 6. Universalizing Faith: This stage is defined by feeling at one with Source/God/Universal Spirit etc.... People here invest their lives in a larger cause without being concerned by the personal cost.
These stages are simply frameworks of understanding people and where they are in regard to their faith. " And I will add, there is much debate about theories of development in general.. so take this info as a guide and not as an absolute.
Now please note that there is no 'content of faith' ie: Christianity, Islamic..etc to this concept of faith development. Which is why I've always liked it. And it also speaks to a larger humanistic need for meaning.. how we answer that for ourselves, is... what I call our own spiritual path. At one point or another in our lifetimes most of us come to a question.. "Is there a 'More'? " to use William James' term.
How we answer that.. I think.. depends on our unique view of this world.. (based on our upbringing, culture, innate nature, personal life experiences..etc) if we see this world as fundamentally hostile, indifferent, gracious.. that will shape the spiritual path we take. (and/or avoid)