Let's start by appreciating that when we speak about the will and thinking (feeling being in between) we have a fundamental
asymmetry. It's one thing to speak about polarity of hearing and sight for example, or left and right hand, then to argue which is more fundamental, it's altogether different to compare two poles of which we could never know one, if we only knew the other. We can easily imagine having only hearing or only sight but we can't
know experience of only will, without the thinking pole. The other is possible - we can easily imagine a state of only thinking without feelings and bodily will and sensory perceptions. So there's fundamental asymmetry here.
Things are very clear but we must not fall for the blind spot. In other words we need the
exceptional state - we need to be aware of our cognitive activity. The simple fact is that Thinking is the expression of our knowing activity. Without it we would never
know that feeling or willing exist. This is the simple fact that so easily falls in the blind spot. We experience thoughts (words for example), we have feelings, we have will impulses and perceptions. If we imagine these in front of us and discard the thoughts we can easily make the mistake: "there, I discarded thinking, I only have feelings and will now and I'm still conscious". This simply fails to understand what is called Thinking. It's the spiritual activity that animates the thoughts and cognizes all perceptions, feelings, will (that is, experiences meaning, intuitive understanding in relation to them). If we manage to transform this activity such that we don't produce thought-forms (words, symbols, etc.), we're still a cognizing Spirit! We still cognitively experience feelings and will and maybe even higher order perceptions with their corresponding higher-order ideal counterparts. We imagine thinking, feeling and willing as spread out before us but they are actually one within the other, so to speak, like Russian dolls (again, we should not be thinking of literal geometric relations).
In the course of evolution our Spiritual core awakens in the innermost sphere. As said, it's not at all difficult to attain to a state of pure thinking without any presence of feelings, desires, bodily sensations, will. But if we drop the innermost sphere we simply lose consciousness. Even if we assume that the other spheres are there, we simply can't know this.
The reality of the will is furthest away from our thinking core. We're completely oblivious of what happens in our muscles for example when we will the movement of our arm. We simply send our spiritual intent which sinks in the darkness and we find its effects only in the bodily and sensory perceptions. We have no clue what happens through the dark zone, between our conscious will-intent and its perception through the bodily senses. We are fully asleep about the processes in that dark zone.
Feeling is a little closer. It's still a world of mystery for us, it confronts us as something semi-independent, sometimes we can interact with it, we can arouse a feeling through our activity, but as a whole they approach us as from another world, which we grasp only vaguely, as in a fuzzy dream.
Finally in thinking we are fully awake. The perceptions of the thoughts and the spiritual world where the causes of these thoughts belong, are united in thinking.
Please note that in our ordinary consciousness we don't know
the reality of feeling and willing. We only know how they
impress into our bodily cognition.
For Kant the whole greyed area is the thing-in-itself. We only know the white sphere of thinking and the perceptions (representations, mental images). The border between the white sphere and the greyed area is completely impassible.
Schopenhauer finds a point of contact with the greyed area. For him the Will includes the whole greyed area - all the urges, desires, needs, cravings, etc. (more refined Western thought differentiates bodily will, where the Spirit meets the physical world, from feelings, desires, etc.) For him the human intellect (thinking sphere)
"is like a lame man who can see, but who rides on the shoulders of a blind giant". And this is actually correct observation. This is how life actually looks like for a major part of humanity. With a complete lack of spiritual education, people float like leaves on the flow of unconscious impulses. They simply call them 'my desires', as if they can choose to have them or not. For Schopenhauer this aimless will is the source of all suffering (after the satisfaction of every desire another comes in and so on). The only thing for him which can alleviate this pain is aesthetic contemplation.
"…aesthetic pleasure in the beautiful consists, to a large extent, in the fact that, when we enter the state of pure contemplation, we are raised for the moment above all willing, above all desires and cares; we are, so to speak, rid of ourselves."
(Schopenhauer, The World as Will and Representation, vol. I, § 68, Dover page 390)
This is the best we can do, and what is wisdom for Schopenhauer. Cognition is as an epiphenomenon patched on top of the blind giant. This is the way many Eastern schools see things (Eugene, I know that there are other Eastern schools which don't do that). It's the realization of the Sisyphus myth. Consciousness rises above the surging sea of will or feeling only to become aware of all the suffering. The return to the sea is the only escape. Schopenhauer at least adds the possibility for the temporary alleviation of suffering through aesthetic contemplation, where consciousness can disconnect from its suffering-prone Will counterpart.
All this is very different in the Western metamorphic view. Please note that I'm not talking about right vs. wrong. We can see how there's gradation from Kant, through Schopenhauer, Hegel, Steiner. For Hegel the white sphere is not at all some epiphenomenon. Archetypal thoughts are the very foundation of reality. Of course Hegel's philosophy is also only a milestone. He never left the sphere of the intellect. He built the world out of
intellectual thoughts (of course in a much deeper sense and not out of abstract thoughts existing in the head). We can never do justice to Hegel's philosophy in few words but let us just appreciate the stark contrast with the previous views - for him the foundations of reality are
cognizable, they are of
thought nature.
It takes a bridge between the intellect and the higher spheres if we are to grow beyond the white sphere in full consciousness (and not only deal with the shadows of will and feelings in our ego consciousness). These are the methods of Initiatic science which was Steiner's task to disclose to the world. Through Imaginative, Inspirative and Intuitive cognition we can penetrate the greyed area in full consciousness. For example, only through Intuitive cognition we can live and have consciousness in the sphere of Will. Here we really find the World Will but not as aimless, surging and suffering sea but as fully conscious, ideating activity of Spirits.
In the metamorphic view it's not about seeking some static equilibrium between thinking and the
shadow of will that we experience in our ego consciousness. It's about the gradual growth in consciousness which penetrates cognitively in the depths of the greyed spheres. The penetration in the feeling sphere is the most understandable and I've given different examples so far. It's about unveiling the world of our hidden desires and their related karmic entanglements, and bringing them to light. The more we purify our desires the more selfless we become. Selfless doesn't mean centerless or without individual perspective. It means that we outgrow our personal egoic interests and begin to consciously participate in the work of the Guiding Spirits. We can imagine that in meditation the white sphere drops the rigid thought-forms and metamorphically grows to merge with the feeling sphere where it becomes lucid cognition of the processes there. I repeat that within our ordinary consciousness, feelings are only the dreamy shadows of spiritual processes in that sphere. The more we grow towards the Will sphere, the more Cosmic-scale our consciousness becomes. Only there we can find, through the highest forms of cognition, the ideating activity which supports our inner and outer World. The Will at the highest sphere is
not at all the will in the way we understand it through its shadow in the ordinary thinking sphere. If we draw an analogy with physics, we can say that the fundamental spiritual forces are united in the spiritual activity of pure Intuition in the highest worlds. Just as the physical forces differentiate, so through the
involutionary iterations the spiritual forces 'delaminate', they differentiate, but not side by side, as symmetrical objects, but 'vertically', as cocoons within cocoons, as Russian dolls. This gives that differentiation the characteristic
asymmetry. We have the
cognitive character of the fundamental force within thinking but the forms of activity left behind in the higher spheres impress in our cognition only as dream-like feelings and dark will (the spiritual forces operating in the physical world which we are unconscious of in our ordinary state).
Once again we see how endless quarrels about right and wrong are magically resolved when we see things through metamorphic-evolutionary perspective. As long as we argue within the flat projection "which is more primary - shadow willing or thinking", we completely miss the point. So Steiner didn't simply want to take a jab at Schopenhauer by outwitting him through some clever logical arguments. His whole life was dedicated to show the path that cognitively penetrates the spheres in
full consciousness. If this is not grasped, the intellect will always see things as kid's fight about 'whose sphere is more important'.