This is a rather difficult question to answer given that most of the biographical details we have about Alexander come from sources that greatly predate him (i.e. Plutarch and Arrian).

Plutarch (Life of Alexander VII.5) says that "Alexander not only received from his master [Aristotle] his ethical and political doctrines, but also participated in those secret and more profound teachings which philosophers designate by the special terms "acroamatic" and "epoptic," and do not impart to many."

Further, he adds that Alexander sent Aristotle a letter "on behalf of philosophy" (v. 6) which reads: "Alexander, to Aristotle, greeting. Thou hast not done well to publish thy acroamatic doctrines; for in what shall I surpass other men if those doctrines wherein I have been trained are to be all men's common property? But I had rather excel in my acquaintance with the best things than in my power. Farewell."

We also must bear in mind that there was no notion of "philosophy" as a strictly delineated discipline, and medicine, physics, (proto-)economics, and literature all would have comfortably fit under the purview of a "philosopher" and the education of one. Thus, (Life of Alexander VIII) Plutarch speaks of Alexander knowing and cherishing "the art of healing" which Aristotle imparted to him, as well as holding fast to a recension of the Iliad by Aristotle. It is in this section that we find the origin of the famous quote: "Aristotle he admired at the first, and loved him, as he himself used to say, more than he did his father, for that the one had given him life, but the other had taught him a noble life".

Arrian (writing in the first half of the 2nd century) makes one mention of Alexander's philosophical tutelage in his Anabasis of Alexander (I.1.3), saying that "in his youth he was placed under the tuition of Aristotle, who acquired very great influence over his mind and character."