• Ideality: mind-dependence; in the mind (in uns)
• Reality: mind-independence; external to the mind (ausser uns)

• Ideality: private data of an individual mind
• Reality: intersubjective spatial-temporal objects of human experience

• Ideality: universal, necessary, a priori conditions of human knowledge, e.g. space and time, the forms of sensibility
• Reality: referring to an independence to any appeal to these conditions

• Appearances: "mental", as an object seems
• Thing-in-itself: "physical", as it "really is"

• Appearances: conforming to human sensibility
• Thing-in-itself: independent of the conditions of human sensibility

• While it is certainly possible that Kant has been greatly misunderstood in the standard picture of his transcendental idealism, I think it may also be possible that Kant himself did not fully understand his own position, which could explain why he frequently seems to use misleading terms like "mere appearances" which are frequently used to support the standard picture.

• Berkeleian ideas and Humean impressions are given to the mind as they are in-themselves and thus confuse the appearances in the empirical sense with the things-in-themselves in the transcendental sense.
• Cartesian dualism regards appearances (in the transcendental sense) with things-in-themselves (also in the transcendental sense)

everything intuited in space and time, and therefore all objects of any experience possible to us, are nothing but appearances, that is, mere representations, which, in the manner in which they are represented, as extended beings, or as a series of alterations, have no independent existence outside our thoughts.

• Allison uses the terms "outer" and "inner" sense, but only ever explicitly defines outer sense/perception as empirically external, spatial objects. What is inner sense, is that space and time?

“From this antinomy we can, however, obtain, not indeed a dogmatic, but a critical and doctrinal advantage. It affords indirect proof of the transcendental ideality of appearances - a proof which ought to convince any who may not be satisfied by the direct proof given in the Transcendental Aesthetic. This proof would consist in the following dilemma. If the world is a whole existing in itself, it is either finite or infinite. But both alternatives are false (as shown in the proofs of the antithesis and thesis respectively). It is therefore also false that the world (the sum of all appearances) is a whole existing in itself. From this it then follows that appearances in general are nothing outside our representations - which is just what it meant by their transcendental ideality.” — Kant

The antithesis asserts that the world can have no beginning in time and no limit in space. Allison breaks it down as follows:
1.) Assume the world has a beginning in time.
2.) The concept of a temporal beginning presupposes a preceding time before the thing exists.
3.) Therefore it is necessary to think of an empty time before the world existed.
4.) But such points of time cannot be distinguished from one another.
5.) A world cannot meaningfully be said to have come into existence at one time rather than another time if both times are empty.
6.) So we cannot meaningfully say the world came into being in time at all, therefore the world is infinite with respect to past time. — darthbarracuda

The argument here contains two suppressed premises: that the antecedent proposition (the world is a whole existing in itself, a totum syntheticum) is entailed by transcendental realism, and that transcendental realism and transcendental idealism are mutually exclusive and exhaustive positions. The negation of the antecedent entails the negation of transcendental realism, which entails the affirmation of transcendental idealism. — darthbarracuda

On the other hand, the law of causality and the treatment and
investigation of nature which is based upon it, lead us necessarily
to the conclusion that, in time, each more highly organised state
of matter has succeeded a cruder state: so that the lower animals
existed before men, fishes before land animals, plants before
59
fishes, and the unorganised before all that is organised; that,
consequently, the original mass had to pass through a long series
of changes before the first eye could be opened. And yet, the
existence of this whole world remains ever dependent upon the
first eye that opened, even if it were that of an insect. For such an
eye is a necessary condition of the possibility of knowledge, and
the whole world exists only in and for knowledge, and without
it is not even thinkable. The world is entirely idea, and as such
demands the knowing subject as the supporter of its existence.
This long course of time itself, filled with innumerable changes,
through which matter rose from form to form till at last the
first percipient creature appeared,—this whole time itself is only
thinkable in the identity of a consciousness whose succession
of ideas, whose form of knowing it is, and apart from which, it
loses all meaning and is nothing at all. Thus we see, on the one
hand, the existence of the whole world necessarily dependent
upon the first conscious being, however undeveloped it may
be; on the other hand, this conscious being just as necessarily
entirely dependent upon a long chain of causes and effects which
have preceded it, and in which it itself appears as a small link. [039]
These two contradictory points of view, to each of which we are
led with the same necessity, we might again call an antinomy
in our faculty of knowledge, and set it up as the counterpart
of that which we found in the first extreme of natural science.
The fourfold antinomy of Kant will be shown, in the criticism
of his philosophy appended to this volume, to be a groundless
delusion. But the necessary contradiction which at last presents
itself to us here, finds its solution in the fact that, to use Kant's
phraseology, time, space, and causality do not belong to the
thing-in-itself, but only to its phenomena, of which they are the
form; which in my language means this: The objective world,
the world as idea, is not the only side of the world, but merely
its outward side; and it has an entirely different side—the side of
its inmost nature—its kernel—the thing-in-itself. This we shall
60 The World As Will And Idea (Vol. 1 of 3)
consider in the second book, calling it after the most immediate
of its objective manifestations—will. But the world as idea,
with which alone we are here concerned, only appears with the
opening of the first eye. Without this medium of knowledge it
cannot be, and therefore it was not before it. But without that eye,
that is to say, outside of knowledge, there was also no before, no
time. Thus time has no beginning, but all beginning is in time.
Since, however, it is the most universal form of the knowable, in
which all phenomena are united together through causality, time,
with its infinity of past and future, is present in the beginning of
knowledge. The phenomenon which fills the first present must at
once be known as causally bound up with and dependent upon a
sequence of phenomena which stretches infinitely into the past,
and this past itself is just as truly conditioned by this first present,
as conversely the present is by the past. Accordingly the past
out of which the first present arises, is, like it, dependent upon
the knowing subject, without which it is nothing. It necessarily
[040] happens, however, that this first present does not manifest itself
as the first, that is, as having no past for its parent, but as
being the beginning of time. It manifests itself rather as the
consequence of the past, according to the principle of existence
in time. In the same way, the phenomena which fill this first
present appear as the effects of earlier phenomena which filled
the past, in accordance with the law of causality. Those who
like mythological interpretations may take the birth of Kronos
(«£ø½ø¬), the youngest of the Titans, as a symbol of the moment
here referred to at which time appears, though, indeed it has
no beginning; for with him, since he ate his father, the crude
productions of heaven and earth cease, and the races of gods and
men appear upon the scene.
This explanation at which we have arrived by following the
most consistent of the philosophical systems which start from the
object, materialism, has brought out clearly the inseparable and
reciprocal dependence of subject and object, and at the same time
61
the inevitable antithesis between them. And this knowledge leads
us to seek for the inner nature of the world, the thing-in-itself,
not in either of the two elements of the idea, but in something
quite distinct from it, and which is not encumbered with such a
fundamental and insoluble antithesis.

— Schopenhauer- World as Will and Representation

Thus we see already that we can never arrive at the real nature
of things from without. However much we investigate, we can
never reach anything but images and names. We are like a man
who goes round a castle seeking in vain for an entrance, and
sometimes sketching the façades. And yet this is the method that
has been followed by all philosophers before me.

The double knowledge which each of us has of the nature and
activity of his own body, and which is given in two completely
different ways, has now been clearly brought out. We shall
accordingly make further use of it as a key to the nature of
every phenomenon in nature, and shall judge of all objects which
are not our own bodies, and are consequently not given to our
consciousness in a double way but only as ideas, according to the
analogy of our own bodies, and shall therefore assume that as in
one aspect they are idea, just like our bodies, and in this respect
First Aspect. The Objectification Of The Will. 151
are analogous to them, so in another aspect, what remains of
objects when we set aside their existence as idea of the subject,
must in its inner nature be the same as that in us which we
call will. For what other kind of existence or reality should we
attribute to the rest of the material world? Whence should we take
the elements out of which we construct such a world? Besides
will and idea nothing is known to us or thinkable. If we wish to
attribute the greatest known reality to the material world which
exists immediately only in our idea, we give it the reality which
our own body has for each of us; for that is the most real thing
for every one. But if we now analyse the reality of this body and
its actions, beyond the fact that it is idea, we find nothing in it
except the will; with this its reality is exhausted. Therefore we
can nowhere find another kind of reality which we can attribute
to the material world. Thus if we hold that the material world is
something more than merely our idea, we must say that besides
being idea, that is, in itself and according to its inmost nature,
it is that which we find immediately in ourselves as will. I say
according to its inmost nature; but we must first come to know [137]
more accurately this real nature of the will, in order that we may
be able to distinguish from it what does not belong to itself, but
to its manifestation, which has many grades. Such, for example,
is the circumstance of its being accompanied by knowledge,
and the determination by motives which is conditioned by this
knowledge. As we shall see farther on, this does not belong to the
real nature of will, but merely to its distinct manifestation as an
animal or a human being. If, therefore, I say,—the force which
attracts a stone to the earth is according to its nature, in itself,
and apart from all idea, will, I shall not be supposed to express
in this proposition the insane opinion that the stone moves itself
in accordance with a known motive, merely because this is the
way in which will appears in man.28 We shall now proceed
28 We can thus by no means agree with Bacon if he (De Augm. Scient., L.
iv. in fine.) thinks that all mechanical and physical movement of bodies has
152 The World As Will And Idea (Vol. 1 of 3)
more clearly and in detail to prove, establish, and develop to its
full extent what as yet has only been provisionally and generally
explained.29
§ 20. As we have said, the will proclaims itself primarily in the
voluntary movements of our own body, as the inmost nature of
this body, as that which it is besides being object of perception,
idea. For these voluntary movements are nothing else than the
visible aspect of the individual acts of will, with which they are
directly coincident and identical, and only distinguished through
the form of knowledge into which they have passed, and in which
alone they can be known, the form of idea.

Thus, although every particular action, under the
presupposition of the definite character, necessarily follows
from the given motive, and although growth, the process of
nourishment, and all the changes of the animal body take place
according to necessarily acting causes (stimuli), yet the whole
series of actions, and consequently every individual act, and
also its condition, the whole body itself which accomplishes
it, and therefore also the process through which and in which it
exists, are nothing but the manifestation of the will, the becoming
visible, the objectification of the will. Upon this rests the perfect
suitableness of the human and animal body to the human and
animal will in general, resembling, though far surpassing, the
correspondence between an instrument made for a purpose and
the will of the maker, and on this account appearing as design,
i.e., the teleological explanation of the body. The parts of the [141]
body must, therefore, completely correspond to the principal
desires through which the will manifests itself; they must be the
visible expression of these desires. Teeth, throat, and bowels
are objectified hunger; the organs of generation are objectified
sexual desire; the grasping hand, the hurrying feet, correspond to
the more indirect desires of the will which they express. As the
human form generally corresponds to the human will generally,
so the individual bodily structure corresponds to the individually
modified will, the character of the individual, and therefore it is
throughout and in all its parts characteristic and full of expression.
It is very remarkable that Parmenides already gave expression
to this in the following verses, quoted by Aristotle (Metaph. iii.
5):—
(Ut enim cuique complexio membrorum flexibilium se habet,
ita mens hominibus adest: idem namque est, quod sapit,
membrorum natura hominibus, et omnibus et omni: quod enim
plus est, intelligentia est.)30
§ 21. Whoever has now gained from all these expositions
a knowledge in abstracto, and therefore clear and certain, of
what every one knows directly in concreto, i.e., as feeling, a
knowledge that his will is the real inner nature of his phenomenal
being, which manifests itself to him as idea, both in his actions
and in their permanent substratum, his body, and that his will
is that which is most immediate in his consciousness, though it
has not as such completely passed into the form of idea in which
[142] object and subject stand over against each other, but makes
itself known to him in a direct manner, in which he does not
quite clearly distinguish subject and object, yet is not known
as a whole to the individual himself, but only in its particular
acts,—whoever, I say, has with me gained this conviction will
find that of itself it affords him the key to the knowledge of the
inmost being of the whole of nature; for he now transfers it to
all those phenomena which are not given to him, like his own
phenomenal existence, both in direct and indirect knowledge,
but only in the latter, thus merely one-sidedly as idea alone. He
will recognise this will of which we are speaking not only in
those phenomenal existences which exactly resemble his own,
in men and animals as their inmost nature, but the course of
reflection will lead him to recognise the force which germinates
and vegetates in the plant, and indeed the force through which the
crystal is formed, that by which the magnet turns to the north pole,
the force whose shock he experiences from the contact of two
different kinds of metals, the force which appears in the elective
affinities of matter as repulsion and attraction, decomposition

The will as a thing in itself is quite different from
its phenomenal appearance, and entirely free from all the forms
of the phenomenal, into which it first passes when it manifests
160 The World As Will And Idea (Vol. 1 of 3)
itself, and which therefore only concern its objectivity, and are
foreign to the will itself. Even the most universal form of all
idea, that of being object for a subject, does not concern it;
still less the forms which are subordinate to this and which
collectively have their common expression in the principle of
sufficient reason, to which we know that time and space belong,
and consequently multiplicity also, which exists and is possible
only through these. In this last regard I shall call time and space
the principium individuationis, borrowing an expression from
[146] the old schoolmen, and I beg to draw attention to this, once
for all. For it is only through the medium of time and space
that what is one and the same, both according to its nature and
to its concept, yet appears as different, as a multiplicity of coexistent and successive phenomena. Thus time and space are the
principium individuationis, the subject of so many subtleties and
disputes among the schoolmen, which may be found collected
in Suarez (Disp. 5, Sect. 3). According to what has been
said, the will as a thing-in-itself lies outside the province of the
principle of sufficient reason in all its forms, and is consequently
completely groundless, although all its manifestations are entirely
subordinated to the principle of sufficient reason. Further, it is
free from all multiplicity, although its manifestations in time
and space are innumerable. It is itself one, though not in the
sense in which an object is one, for the unity of an object can
only be known in opposition to a possible multiplicity; nor
yet in the sense in which a concept is one, for the unity of a
concept originates only in abstraction from a multiplicity; but it
is one as that which lies outside time and space, the principium
individuationis, i.e., the possibility of multiplicity. Only when
all this has become quite clear to us through the subsequent
examination of the phenomena and different manifestations of
the will, shall we fully understand the meaning of the Kantian
doctrine that time, space and causality do not belong to the
thing-in-itself, but are only forms of knowing.

Thus we see already that we can never arrive at the real nature
of things from without. However much we investigate, we can
never reach anything but images and names. We are like a man
who goes round a castle seeking in vain for an entrance, and
sometimes sketching the façades. And yet this is the method that
has been followed by all philosophers before me.

every x that is under the concept (a + b) is also under the concept b

every x that is under the concept (a + b) is also under the concept c

“Knowledge is a judgement from which a concept arises that has objective validity, i.e., to which a corresponding object in experience can be given. All experience, however, consists of the intuition of an object, i.e., an immediate and singular representation, through which the object is given to knowledge, and of a concept, i.e., a mediate representation through a mark which is common to several objects, through which it is thought. One of these two modes of representation alone cannot constitute knowledge, and if there is to be synthetic knowledge a priori, there must also be a priori intuitions as well as concepts.” — Kant

I'm also a sucker for old books. — darthbarracuda

"Insofar as Da-sein temporalizes itself with regard to its being it is the world... The world is neither objectively present nor at hand, but temporalizes itself in temporality.. If no Da-sein exists, no world is 'there' either." Heidegger, 1927 — Gregory

There is no empirical evidence that the train would have hit me if I would have stayed on the railroad, — Art Stoic Spirit

True. But there is a ton of empirical evidence that justifies the claim no two physical objects can occupy the same space at the same time. — Mww

Can’t argue with your logic. — Mww

Kant's investigations in the Transcendental Logic lead him to conclude that the understanding and reason can only legitimately be applied to things as they appear phenomenally to us in experience. — Art Stoic Spirit

Kant went to great length to prove the possibility of a priori cognitions, the objects of which do not arise naturally from phenomena, re: mathematics and geometry. From that, it is the case pure reason and pure understanding, have no legitimacy in experience. — Mww

If this correct the same rules apply to such abstract concepts as spirituality, inner motivation, soul, or universal ethics. Kantian ethics. — Art Stoic Spirit

“Space is not an empirical concept which has been derived from outer experiences. For in order that certain sensations be referred to something outside me (that is, to something in another region of space from that in which I find myself), and similarly in order that I may be able to represent them as outside and alongside one another, and accordingly as not only different but as in different places, the representation of space must be presupposed. The representation of space cannot, therefore, be empirically obtained from the relations of outer experience. On the contrary, this outer experience is itself possible at all only through that representation. — Kant

“Space, represented as object (as we are required to do in geometry), contains more than mere form of intuition; it also contains [gives/supplies] combination of the manifold, given according to the form of sensibility, in an intuitive representation, so that the form of intuition gives only the manifold, the formal intuition gives the unity of representation.” — Kant

“It is, therefore, solely from the human standpoint that we can speak of space, of extended things, etc. If we depart from the subjective condition under which alone we can have outer intuition, namely, liability to be affected by objects, the representation of space stands for nothing whatsoever. This predicate can be ascribed to things only insofar as they appear to us, that is, only to objects of sensibility.” — Kant

Kant says "matter's motion or rest merely in relation to the mode of representation or modality, and *thus* to appearance of the outer sense, is called phenomenology." — Gregory