The issue you should be studying is Aristotle's criticism of Plato's 'theory of ideas'. The reason being that the term 'idealism' didn't come into vogue until much later - in the 18th century, or so. Retrospectively, Plato was then categorised as idealist, but 'idealism' is a term that is found in neither Plato nor Aristotle. And in this matter that is an important point, as the choice of terms and the way they are used can subtly influence the conclusions you reach about it. In fact I think you would be hard-pressed to find the expression that 'reality consists of...' in any pre-modern authors, as that level of abstraction is more typical of modernism.

Thanks. I think you are completely correct in your analysis. :)

This was just a hypothetical question in the sense of "What if we could teleport Aristotle into a room with some of the great 18th-century idealists such as Kant, Fichte, Hegel, or Schelling"? I'm sure he would think idealism was Platonism gone amuck but how would he argue that? :)

The problem I invariably find with Kant, Fichte, Schelling, et al, is the enormously complicated and voluminous nature of their works. I am very much a Kant fan, and also have a lot of time for Schopenhauer, but as when you get into the intricacies of later German idealism, the whole thing tends to collapse under the weight of its own verbiage.

As far as Aristotle was concerned - there's an element of the common-sense realist about him. It is often pointed out that in the famous Raphael portrait of Plato and Aristotle, Plato is pointing up, Aristotle's hand is held out palm facing downwards. Plato the mystic, Aristotle the scientist. But again, it's a deep topic, to really understand Plato's theory and Aristotle's criticism of it, takes a lot of reading.

In Western philosophy, you could argue that there has been an ongoing dialectic between materialism ('ultimate object') and idealism ('ultimate subject') that has gone back and forth for generations. Scientific materialism has been in the ascendant in the mainstream of secular culture for a good while, but now might be on the outer, for various complex reasons.

But they're all very large questions. Probably better to try and narrow the scope of what you're asking.

How would Aristotle respond to idealism? (I understand that there are many types of idealism but I'm thinking in general terms - the concept that all reality consists of mind and its ideas?) What would Aristotle say about this concept? — DS1517

The question is framed through our modern-day Cartesian spectacles. Is it mind, matter, or is it both distinct and incommensurable substances acting in parallel? Mirroring what Wayfarer said, to my best knowledge, this contextualization—this means of compartmentalizing and viewing—that which is never held a significant foothold prior to Descartes. (Noteworthy: Among pre-Socratics there were however occasional suppositions of everything being one of the five elements—Earth, Water, Fire, Air, or some varient of what is now sometimes addressed by the Sanskrit Akasha (e.g. the Apeiron)—but I strongly believe these basic elements meant things far different than what we now most often interpret them to be via our Cartesian glasses. For example: water, fire, air, and void (the latter being one commonly known take on the fifth element; again, others can be found) could not have been meant to have been physical—at least not by the more learned crowds—but metaphysical. For were these elements to have been physical (e.g. Heraclitus addressing physical fire rather than a metaphysical property or process of transformation which is only tangibly represented by physical fire), then they all would have pertained to the one basic substance of Earth (matter/mother, Gaia, Scythian notions of Pon, non-satyr interpretations of Pan, the matrix (womb) … to list just a few ancient concepts for the physical, most of which strongly differ from our own in significant ways.)

But as to Aristotle’s more down to earth approach relative to Plato, one of the more pivotal elements of his philosophy was that of teleological causation—very much including there being a first teleological cause to all that otherwise is. To a Cartesian-contextualized mindset we currently live in, this primordial final cause (the unmoved given that teleological moves everything which is remotely other) cannot be neatly compartmentalized into either materialism or substance dualism.

A small side-note for technical purposes: to Aristotle this primordial final cause is some given that holds real presence and not what we would affirm as nothingness. (A wink to Apokrisis)

So my inference: Given the common modern mindset that only these three possibilities exist—again, that of materialism, idealism, and substance dualism—Aristotle, for the reasons just provided, would then by default fall within the one category that remains: idealism.

However, whether or not Aristotle would have himself taken issue with this label where he to have been alive today … I’ve no way of knowing. And, again, I very much agree that this forced choice between Cartesian substances of mind v. matter would have been utterly foreign to Aristotle.

But I’ve mainly added my thoughts within this thread because I’m honestly curious (this after my best attempts at reading the writing on the walls):

To use a post-Cartesian notion provided by Charles S. Peirce: if everything physical were to be nothing else but effete mind, what difference would it make for all practical purposes as regards anything physical?

(There’s at minimum this one connection between Peirce’s Objective Idealism and Aristotelianism: both maintain a globally applicable, primordial final cause—which is neither of a materialism nor a dual substance mindset (if it needs stating, this without denying all the un-pleasantries that occasionally are to be found within reality.))