Why didn't the Phoenicians develop rational thinking? After all, they had writing and they traded far and wide, just like the Greeks. So why didn't the Phoenicians develop logic?
There are a number of reasons why the Phoenicians didn't lead the way. First, their form of trade was royal, not private. That is, most of the trade that went on in those days was between rulers. There wasn't much of a free market system. Yes, there was some private trading, but the bulk of the trade activity was in items desired by kings. For example, the Phoenicians provided the Egyptians with cedar wood -- but at Pharoah's specific request. They also acted as the entrepot for metals: copper, tin, iron, silver, and gold. Again, this wasn't a matter of buying and selling. Kings traded gifts according to needs, demands, and power relationships. Thus, the Phoenicians supplied the Assyrians with tons of precious metals, with nothing in return -- other than the Assyrians' continued sufference of their independence. It was tribute of a sort.
It is true that many of the trading families also carried out profitable trade on the side, and this bolstered their wealth. However, they operated under the protection and at the guidance of the king. These were, basically, government agents making a little extra on the side. They were not merchants risking their livelihoods on every decision they made. The monopoly granted them by the king insured that they'd always be wealthy.
Perhaps the best indication of the non-public nature of the Phoenician trading system is their failure to develop money. They did develop a rough valuation system using weights of silver for comparing different commodities. But they didn't actually exchange silver; they only used the silver values for different commodities to determine trading ratios.
Another important distinction is that the Phoenicians dealt primarily in luxury goods: small, high-value items that could make a long voyage pay its cost. There is some evidence of Phoenicians trading in lower-value commodities such as grain, but these are few and far between. It is clear that the bulk of their trading was in high-value items such as metals, spices, high-quality manufactures, dyes, and so forth.
It is true that Phoenician ships grew fairly large: the typical trading ships were between 100 tons and 500 tons of displacement. However, their trade routes ran from the Western Mediterranean (Spain, Carthage, Sardia, etc) and Phoenica, which took a full year to make the circuit. For this kind of long-range, long-duration merchant trips, they needed high value per ton of cargo. Foodstuffs were just not valuable enough to sustain this kind of trade. The Phoenicians dealt in metals and expensive manufactured goods.
Another distinction arises from the social structure of trade. The career was not open to anybody; instead, there were large families who dominated trade. They, along with the aristocracy, formed the upper crust of Phoenician society, but they never had to compete with anybody. Their position in society was determined by their family connections, not their success at business. This meant that success or failure in trade had little bearing on one's success in life.
The most important distinction, in my thinking, is the fact that Phoenician society was not dependent upon trade for their food. Yes, they were not quite able to produce sufficient food on their coastal littoral and often imported food, but most food was imported from nearby sources: Israel, Syria, and, to a lesser extent, Egypt. This food importation was not central to their existence as a society. That in turn meant that merchants were not fundamental to the survival of the state and so trade never dominated their thinking the way it did with the Greeks.
Put all this together and you can see why the Phoenicians never developed rationalism: they were never forced to. At no point in history did Phoenician society face a crisis that could only be addressed through rational thought. Necessity is the mother of invention, and the Phoenicians in this regard were orphans.
Source: The Phoenicians and the West, by Maria Eugenia Aubet, Second Edition, 2001