It's important to contextualize Aristotle, farther of science, against Plato and Protagoras, fathers of philosophy. All of the worst impulses of a priori theorizing were in Plato and Protagoras -- from pure blind objectivity to pure blind subjectivity. Aristotle was working hard to defend a study of the world from both of them, delivering ingenuous arguments for realism which are no worse than any given since.

His philosophy is more-or-less a modern scientific realism: the world exists, it has essential properties, knowing the world is knowing these properties, these must be discovered, in general we do not know the accidental from the essential, etc.