Kant, Schopenhauer, and Reality
The first major philosopher to call himself an idealist was Kant. He asserted (if not clearly in the first edition of his Critique of Pure Reason (1781) then in his Prolegomena to Any Future Metaphysics (1783)) that idealism does "not concern the existence of things", but rather identifies that our "modes of representation" of them are not "determinations that belong to things in themselves". Instead, they are features of our own minds. In a desperate effort to prevent confusion with Berkeley's ideas, Kant labored to distinguish his position as empirical realism combined with transcendental idealism—industry jargon for the proposition that space and time are ineliminable properties of our experience but not real properties of things as they are in themselves. In other words, the view that reality is merely a formal feature of how we perceive objects — that it's not, as we'd like to believe, something existing absolutely. Rather, it's a pure form of human intuition contributed by our own faculty of sensibility.
In the Fourth Paralogism, Kant clarifies the following.
To this [transcendental] idealism is opposed transcendental realism, which regards space and time as something given in themselves (independent of our sensibility). The transcendental realist therefore represents outer appearances as things in themselves [Dinge an sich selbst], which would exist independently of us and our sensibility and thus would also be outside us according to pure concepts of the understanding. — The paralogisms of pure reason (A), A369
He expands on this in the Critique.
We have sufficiently proved in the Transcendental Aesthetic that everything intuited in space or in time, hence all objects of an experience possible for us, are nothing but appearances, i.e., mere representations, which, as they are represented, as extended beings or series of alterations, have outside our thoughts no existence grounded in itself. This doctrine I call transcendental idealism. — The Antinomy of Pure Reason Section Six, Transcendental idealism as the key to solving the cosmological dialectic, A491 / B 519
Transcendental is a term that deserves special clarification. By this, Kant means that his philosophical approach goes beyond mere consideration of sensory evidence and requires an understanding of the mind's innate modes of processing that sensory evidence.
In his work, Kant neither denies the existence of things independent from our representations of them nor asserts that these things must be mental in nature; the transcendental idealist part of his position cannot be straightforwardly identified with idealism as he understood it or as we are understanding it here, namely, as the position that reality is ultimately mental in nature. While Kant thinks that he has given a sound argument for the transcendental ideality of space and time, he holds that there is no reason at all to question the existence of things independent from our representations of them. That's where I find, he fails. Kant was close and so was Berkeley but Schopenhauer nailed it.
There are two parts to this story: the object and the subject. The object can be thought of as the collective set of all things perceivable; it's the entire world as we know it. Now, the existence of a perception necessitates a perceiver, the one to whom the perception belongs. This is the subject, the haver of the idea — the being that exercises agency. The sentence you are now reading is the object and you, the subject. What's perhaps worth noting is that these are inseparable. You can't have one without the other — there's no thought without a thinker, and you're not thinking if you don't have thoughts. Any attempt to separate "object" and "subject" into truly different things, rather than parts of the same idea, heralds failure.
But that's not enough nearly enough. We aren't happy being told that reality lies beyond our grasp. Those before Schopenhauer had admittedly approached the problem from the outside looking in, rendering any effort at understanding reality pointless. But Schopenhauer realized that we are in the world as much as anything else; our bodies are objects just like the laptop I'm writing this on. What sets my hand apart from the cup of coffee it holds? What if my body were just the object I'm closest to, and I had no more control over it than your body, which is also an object to me?
So, if objects encompass all perceivable states, and these states don't exist absolutely, what is innate to our reality? Schopenhauer's resolution was the Will. Schopenhauer argues that the world we experience exists solely as "representation" (Vorstellung, German for perception) dependent on a cognizing subject, not as a world that can be considered to exist in itself (i.e., independently of how it appears to the subject's mind). One's knowledge of objects is thus knowledge of mere phenomena rather than things in themselves.
Schopenhauer identifies the thing-in-itself (Ding an sich selbst) — the inner essence of everything — as the Will: a blind, unconscious, aimless striving devoid of knowledge, outside of space and time, and free of all multiplicity. The world as representation is therefore the "objectification" of the Will. Oddly enough, the thing-in-itself is an idea introduced by Kant in his Prolegomena. It is worth noting that Kant offered no resolution here. Schopenhauer's methodic approach nailed a problem that neither Kant nor Berkeley could. He led us to the Will.
And we indeed, rightly considering objects of sense as mere appearances, confess thereby that they are based upon a thing in itself, though we know not this thing as it is in itself, but only know its appearances, viz., the way in which our senses are affected by this unknown something. — Prolegomena, § 32
Schopenhauer's philosophy holds that all nature, including man, is the expression of an insatiable will. It is through the will, the in-itself of all existence, that humans find all their suffering. The desire for more is what causes this suffering. He argues that only aesthetic pleasure creates a momentary escape from the will. Schopenhauer's concept of desire has strong parallels in Buddhist thought. Buddhism identifies the individual's pervasive sense of dissatisfaction as driving craving, roughly similar to what Schopenhauer would call the will to live. Both assert that remedies for this condition include contemplative, ascetic activities.
Schopenhauer says that our Will is all that sets our body apart from any other object; the Will manifests itself in the movement of the body. Emotions? Just violent movements of the Will, as these too cause the body to react, whether the heart races, the hands sweat, or the breathing slows. Only the Will allows us to take the body beyond an object of perception. Aesthetic experiences release one briefly from an endless servitude to the Will, which is the root of suffering. True redemption from life, Schopenhauer asserts, can only result from the total ascetic negation — the indefinite renunciation of all instinct and desire — of the "will to live" (Wille zum Leben). The will to live is an idea Schopenhauer put forth, but similar instances can be found in Freud's pleasure principle. Schopenhauer described it as an irrational "blind incessant impulse without knowledge". There is a fundamental agreement between his philosophies and those of Plato and the ancient Indian Vedas.
What sets man apart is his ability to reason, to replace perception with abstract ideas — not only do we perceive individual things, but we can categorize them and reason about them. No lower being could succeed in such an exercise. The idea behind every abstract idea, the highest idea, is pure unadulterated Idea — the idea of being an object for the subject. It may sound like nonsense rambling at this point but this is the crux of most reason. This Idea is the ultimate reality — Idea itself. But the Idea rests on notions of object and subject and if we strip this away, only one thing remains: the Will, which is the thing-in-itself that Kant thought we couldn't know.
If the whole world as representation is only the visibility of the will, then art is the elucidation of this visibility, the camera obscura which shows the objects more purely, and enables us to survey and comprehend them better. It is the play within the play, the stage on the stage in Hamlet. — Schopenhauer, The World as Will and Representation, Vol. 1, Book III, §52
This was arguably one of the more philosophically convoluted articles I've written and neither Kant's nor Schopenhauer's works are straightforward for the amateur reader. Please let me know if there are any errors here and I'd be happy to correct them. Thank you for your time and have a great day!