Hemingway's contention that what shows in The Old Man and the Sea is just "the tip of the iceberg" seems a particularly accurate assessment of the philosophical and socioeconomic foundations of his characters' behavior. Among the most obvious are the disparate codes that divide the fishermen of Santiago's village into two groups (as critics such as Bickford Sylvester have pointed out).
One group consists of fishermen like Santiago, who respect nature and see themselves as part of it. They rely on their skill and dedication to their craft to participate in nature's eternal pattern. These fishermen are part of a traditional fishing culture that is insulated and isolated from the industrialized world, bereft of modern technology, and bound to extended families and tightly knit communities. These fishermen affectionately refer to the sea as la mar (the Spanish feminine) and recognize both its great beauty and its occasional cruelty. As this group's quintessential representative, Santiago performs each fishing task with the precision of a religious ritual and recognizes his kinship with all the living creatures who share a common fate and nourish one another in nature's eternal cycle.
The other group consists of younger, pragmatic fishermen, who exhibit a profound disregard for nature. They do not rely on their own skill, but on mechanisms (such as motorized boats and fishing lines floated by buoys) to ensure a steady income. These fishermen are part of the material progress of a fishing industry, increasingly dependent on the industrialized world for their livelihood, and much less bound to extended families and local communities. These fishermen refer to the sea as el mar (the Spanish masculine) and consider it a contestant or an enemy to be overcome. Their philosophy informs behavior that robs the natural world and the dedicated fishermen of intrinsic, less tangible values and spiritually satisfying meaning.
In the philosophical differences between these two groups, Hemingway never implies that Santiago disdains economic security. His poverty, his occasional thoughts about winning the lottery, his musings that the marlin's delicate-tasting flesh would have brought a high price at the market, and so forth all indicate how keenly Santiago feels his own economic circumstances. On the contrary, these philosophical differences help underscore just how keenly Santiago craves the intangibles that give life meaning, provide spiritual enrichment, and ensure the redemption of the individual's existence.
Closely connected to Santiago's recognition of the philosophical differences between the two groups are his Job-like musings. He wonders why sea birds are made so delicate when the ocean can be so cruel, which recalls Job's question about why the innocent are made to suffer (as, of course, Santiago himself is made to suffer). He also wonders why those who let their fishing lines drift are more successful than he is, though he keeps his fishing lines precisely straight, recalling Job's question about why the unworthy prosper. Santiago later answers both questions and more when he considers whether killing the marlin was a great sin. He eventually decides that he killed the marlin not for food, but because he is a fisherman. In his understanding resides the echo of God's answer to Job. Essentially, God's answer was that suffering is in the very nature of the universe. Just as enigmatic, Santiago's own understanding is that he did what he had to do, what he was born to do, and what his role in the eternal nature of things demands. That acceptance is both God's and Santiago's answer to why the good are made to suffer (why the sea birds are made so delicate, why Santiago has gone for so long without a catch) and why the unworthy prosper (why those who let their fishing lines drift are more successful).
As Hemingway makes clear, the pragmatic fishermen (like the scavenger sharks with whom they're associated) inevitably must prevail — at least for a time and in accordance with the natural order that makes all creatures both victors and victims. Yet the philosophy of the pragmatic fishermen also sows the seeds of their own economic destruction. So readers may well infer that Manolin will become much more than just the redeemer of Santiago's understanding of his personal experience at the story's end. Manolin and those who succeed him may well become the standard bearers of a philosophy that eventually must come into its own again, though in a new iteration, after a nearly universal pattern of socioeconomic change (familiar even today among developing nations) has carved itself on the rural Cuban landscape.