I'm sure one could write a longer reflective piece on this, but just a few comments and an answer I've written here previously. The general impression of ancient authors was that Aristotle's teachings had a massive impact on Alexander's character and outlook, which might be true, but I don't know how we could assess this in terms of Alexander's concrete actions and decisions; his conquest lifestyle and aspirations are certainly in conflict with Aristotle's philosophy. I have written previously about the fact that we do not actually know much at all what went on in the lessons between Alexander and Aristotle, or how significant the relationship was to Alexander - after all, Aristotle taught Alexander only for a year, when he was 13-14 years old.

The student-teacher relationship between Alexander and Aristotle became idealised already in antiquity, as did Alexander's image as a sort of 'ultimate philosopher-conqueror', and it's very difficult to say what was the actual reality. Plutarch, a Greek philosophical essayist, is probably our fullest ancient source to the relationship between Aristotle and Alexander, as there are no surviving contemporary sources about Alexander's childhood. But, Plutarch is writing about events that took place 400 years before his time, and a lot of idealised fiction will have mixed with the fact by this point. Plutarch credits Aristotle in instilling in Alexander all his political and philosophical doctrines and a love of wisdom, but it's a bit difficult to say what this would mean because, you know, conquering a massive kingdom was wildly inconsistent with Aristotle's philosophy. Although Alexander certainly later in his life promoted Hellenism and Greek culture in various ways, I don't think we can put this all down to Aristotle (as Plutarch does), because a teen-age Macedonian royal prince surely should have received a very diverse Hellenic education from a very young age, long before he met Aristotle.

But, some of the anecdotes Plutarch tells about Alexander's and Aristotle's relationship probably are fact. He for example says that Alexander on his campaigns always slept with a knife and and a copy of Homer's Iliad annotated by Aristotle under his pillow, and sites Onesicritus, who accompanied Alexander to Asia, as his source. Plutarch also had access to the writings of Alexander's contemporary Marsyas of Pella, who could have perhaps provided him with trustworthy anecdotes about Alexander's education.

Here are the two (short) chapter's where Plutarch discusses Aristotle's and Alexander's relationship: Alex. 7 and Alex. 8. I just checked Arrian, our fullest source to Alexander's campaigns in the East (Anabasis, which doesn't include anything about Alexander's childhood), and he doesn't actually mention anything about Aristotle apart from a crazy rumour that he provided a poison that killed Alexander, because he had later in his life started to fear Alexandr.