∼ Prerequisites for Being a Philosopher ∼
Plato (Republic, 7.535a-c) discussing the philosophic nature, targets the would-be philosopher's apptitude for study, his willingness to study, and his love of practice (cf. Dillon, Alcinous, 53).
Republic 7.535a-c:
[Socrates:] "...we have to select the most stable, the most courageous, and as far as possible the most graceful. In addition, we must look not only for people who have a noble and tough character but for those who have the natural qualities conducive to this education of ours."
[Glaucon:] "Which ones exactly?"
[Socrates:] "The must be keen on the subjects and learn them easily, for people's souls give up much more easily in hard study than in physical training, since the pain -- being peculiar to them and not shared with their body -- is more their own."
[Glaucon:] "That’s true."
[Socrates:] "We must also look for someone who has got a good memory, is persistent and is in every way a lover of hard work. How else do you think he'd be willing to carry out both the requisite bodily labours and also complete so much study and practice?"
Aristotle, perhaps basing himself on this, identified three prerequisites for the successful philosopher: his natural aptitude (phusis), his study (mathesis) and his practice (askesis) (cf. Dillon, Alcinous, 52-53).
∼ The Philosopher's Natural Aptitude ∼
Alcinous states that the philosopher must first be one with a natural aptitude for the study of metaphysics. Secondly, he must have a commitment to truth and aversion of falsehood. Thirdly, he must be temperate and self-controlled, his pursuit of truth making him unimpressed with bodily pleasure (Didaskalikos 1.2). Alcinous further states that such an individual, who seeks the greatest knowledge of human and divine matters, must not be petty-minded. He must be naturally disposed towards justice, truth, liberality and temperance. Further, he must be ready for study, possessing a readiness to learn and an excellent memory (Didaskalikos 1.3).
∼ Schole and Philoponia ∼
Socrates, in the Theaetetus (172c-e), states that most men, especially those who engage in the hustle and bustle of civil affairs, have put themselves in situations, with deadlines, pleasing others, pursuing agendas, where they do not have the time (schole) to consider the value or the reality of their endeavours. Thus schole, "leisure time" (from which we derived the word 'school'), becomes an important commodity for the those who would engage in philosophy.
But it isn't having the time that is important. Some people have the time, but when they say that they do not have the time, what they mean, is that they do not want to spend their efforts thinking about things they have already decided about. Why worry about truth, when I've already decided that the current pursuits in my life are what are important for me.
So, it really isn't about having the time, it is about making the time. Only those who value the pursuit of truth and virtue have the philoponia, the love of hard work, needed to be successful at a life of philosophy (cf. Republic 535a-d).
∼ The Philosopher's Study ∼
Alcinous says that an individual with the natural characteristics of a philosopher must receive a "correct education and suitable nurturing", perfecting himself in the cultivation of virtue. Failing this, such philosophical characteristics will cause the soul much suffering (Didaskalikos, 1.4). Plato says that such an individual would be used by society to perpetuate the status quo, not for achieving high ideals, but to further the corrupt pursuits of the mindless market and political manipulation (Republic, 492a ff).
Simplicius (On Aristotle's Categories 1-4, 8.3-8) states that the student must keep from "disputatious twaddle," which some who study logic and philosophical argumentation fall into, who "contradict even what is obvious, blinding the eye of their souls." Simplicius, citing Aristotle (Topics 1.11, 105a3ff.), says that such lovers of argument need either "sensation" (aisthesis), that is, to be shown the real issues involved in an argument, or "punishment" if, having understood the issues, try simply to "show off" their skills at debate without regard for truth.