Final answer:
Philosophers rarely rule due to the mismatch between the pursuit of philosophical wisdom and the pragmatic demands of governance, alongside their characteristic idealism. Philosophy is also challenging, which may limit the number of individuals pursuing the discipline.
Step-by-step explanation:
Philosophers may not rule very often for a number of reasons, but none of the options provided in the question perfectly encapsulates the complexity of the issue. However, examining philosophers like Plato, Aristotle, Al-Farabi, and historical perspectives on government, certain themes emerge. Philosophers, such as Plato and his conception of philosopher-kings, argue that rulers should be wise and possess knowledge of the forms, striving for the good of the community—attaining a form of monarchy or aristocracy. Yet, they also recognized the potential for corruption and the degeneration of these ideal states into tyranny or oligarchy, respectively.
Additionally, the philosophical task requires an understanding of the immaterial realm, and philosophers are thought to possess both practical and theoretical knowledge, making them potentially fit to rule wisely. However, the scarcity of philosophers can be attributed to the nature of philosophy itself. Philosophy is a challenging discipline, requiring a deep understanding of a broad array of subjects without recourse to basic assumptions.
Another factor might be that the temperament and skills that make for a good philosopher, like the pursuit of knowledge and solitude for deep thought, do not necessarily align with the skill set required for a ruler, who must often make practical, immediate decisions that affect the lives of many. Moreover, the job of a philosopher usually involves questioning and challenging the status quo, which can be at odds with holding a position of power in a political system. Philosophers' propensity for critical thought and idealism might not translate well into the pragmatic and often compromise-driven sphere of politics.
Lastly, there's no societal or legal rule preventing philosophers from ruling, but the intersection between the philosophy's pursuit of wisdom and governance's practical challenges makes the philosopher-ruler a rarity. Furthermore, philosophical wisdom is not always congruent with what is politically expedient or popular, so even if philosophers sought to rule, they may not be chosen by those who have power or by the populace in a democracy.