Chapter 6 Chapter 4 On the first class of objects of the subject, and the form of the principle of sufficient reason governing them 2

Section 21 Innate Features of Causal Concepts Intellectual Features of Empirical Intuition The philosophy taught by our professors of philosophy, which still teaches us to this day that intuitions about the external world are matters of the senses, then proceeds to treat the five senses in detail; It is primarily a matter of the understanding, which, through its own form of causality, together with the purely sensuous forms of time and space posited by the law of causality, creates and produces the original objective external world out of sense-data.Its main features, however, were illustrated in the first edition of this treatise of mine, and discussed at greater length shortly thereafter in my Treatise on Sight and Color (1816), Rosas The professor appreciated the paper, but plagiarized its contents②.But our Professor of Philosophy feels that whether it is this doctrine or any other truly great and important truth, although these truths are the goals I have set in my life, I have always striven to explore them, so as to ensure that they can become our human beings. Eternal wealth is dismissive.For it was not to their liking or conception; neither to inspire theology, nor to train students for higher national purposes.In short, professional philosophers are unwilling to learn from me, and do not understand how much they will learn from me that their descendants will learn from me.They would rather sit down and engage in endless metaphysical chatter, each with his own side, and grandstanding; no doubt, if the fingers are entitled enough, the fingers will have the philosophy.According to Hesiod who preceded him, Machiavelli said: "There are three kinds of brains: the first kind is to get knowledge and understanding from things in themselves; the second kind is to receive truth through the knowledge of others; the third kind, Neither." ④—How reasonable this is!

-------- ① 1813, pages 53-55. ②For further information, please see page 19 of the first edition and page 14 of the third edition of my essay "Will in Nature". ③See Hesiod: Theogony, p. 293. ④ See Machiavelli: Chapter 22 of The Prince. A man doomed to be cast out by the gods would surely conceive of an external, perceptible world filling three-dimensional space while moving in irreversible, never-ending time, each step forward by The laws of causality govern without exception, and by following them we can show before applying them that a world like this, we say, exists truly and objectively outside of us, independent of ourselves, only It has to be transmitted to our brain through pure sensation, so there is a second existence that seems to be outside us but inside us.However, feeling is a very poor thing after all!Even the highest of our organs is nothing but a narrow, concrete sense, susceptible to even slight variations, always in itself subjective, and therefore , cannot contain objective content, and anything like intuition.For sensation is and always is a process within our organism, and is confined within our skin; therefore it cannot contain anything outside this sphere, that is, outside us.A sensation can be agreeable or unpleasant—which predicts a relation to the will—but there is no objective content in the sensation.In the sensory organs, due to the aggregation of nerve endings, the senses are sublimated, and because they are widely distributed and the capsules that close them are sensitive, the senses are easily stimulated by external factors; in addition, they are very easily affected by individual things, such as light, Sounds, smells, but it is still nothing but sensations, like everything else in our body, so it is inherently subjective and we are only directly aware of its changes through the form of the inner senses, namely time, that is, successive .Only when the intellect comes into play—not a single tiny nerve ending, but a mysteriously complex structure, which is our brain, which weighs no more than five to ten pounds—only when it starts to use its Only form: the law of causality, a powerful transformation takes place by which subjective perception becomes objective intuition.For, according to its own proper form, that is, a priori, that is, a form prior to any experience (because there is nothing before it), the understanding conceives as a result a certain corporeal sensation (a word understood only by the understanding) , so that if there is an effect, there must be a cause.At the same time it has recourse to space, the form of the outer sense, which is likewise in the intellect (i.e., the brain), in order to remove the cause from the organism; Only space makes this possible, since a priori pure intuition must provide the basis for empirical intuition.In this process the understanding makes use of the various materials provided by the senses, even the most subtle ones, in order to form causes which are spatially consistent with these materials.We will soon see this process more clearly.This intellectual activity (directly denied by Schelling1 and Fries22) cannot in any case take place abstractly in the form of inferences and reflections in concepts and words; on the contrary, this activity is an immediate process of intuition.For only in this way can the real, objective, corporeal world, which fills the real, objective, corporeal world, exist in the understanding and only for the understanding, express itself and further produce changes in time and motions in space according to the same law of causality. —It is the understanding itself, therefore, which creates the objective world; for this world cannot enter our brain from outside in formed form through the channels of the senses and sense organs.In fact, the senses furnish only the raw material, which the intellect at once processes, according to laws, through the simple forms we have already discussed: space, time, and causality, into an objective image of the corporeal world.Therefore, the empirical intuition that we do every day is an intellectual activity, we have the right to say so.The German pseudo-philosophers interpreted this as a disguised intuition in the realm of dreams, whereby their preferred "absolute" evolved.We shall now proceed to show how wide a chasm the distinction between perception and sensation draws, because the understanding has erected a magnificent edifice on the crudest materials provided by the senses.

-------- ① Schelling: "Philosophical Writings" (1809), Volume I, Pages 237 and 238. ② Fries: "Critique of Reason", first edition, volume 1, pp. 52-56, p. 290. To be precise, objective intuition uses only two senses: touch and sight.Only these two senses furnish the material for the understanding, on the basis of which it constructs the objective world by the process just described.The other three senses are entirely subjective; for their sensations, while oriented toward external causes, contain no material by which their spatial relations can be determined.Space is the form of all intuition, that is, comprehension. To be precise, only in this form of space can the object present itself.These other three senses, therefore, can undoubtedly be used to foretell the existence of objects of which we are otherwise aware; but the material provided by them makes it impossible to form spatial constructions, and thus objective intuitions.The existence of the rose cannot be based on its fragrance, and the blind man can enjoy music all his life without having the slightest objective appearance of musicians or instruments or the vibrations of space.On the other hand, hearing is crucial as a mediator of language, and it is for this reason that reason has meaning.Hearing has the same value in music, the only form in which we can apprehend quantitative relations both abstractly and immediately concretely; We approach the essence of its cause; if we stop here, the result is that the understanding has no material with which to construct the objective world.Only touch and sight furnish this material; thus the blind man, even without hands or feet, systematically constructs space for himself a priori, although he has only a very vague representation of the objective world.What is provided by touch and sight, however, is not in any way intuitive, but at best its raw material.Since intuition can never be contained in the senses of touch and sight, these senses do not even have any essential resemblance to the things through which they present themselves to us, which I shall presently treat.We would do well at the outset to make a clear distinction between what belongs to the senses and what is intellectually processed in intuition.At the beginning this was not easy, because we are accustomed to ask its cause directly from the sensation, so that the cause presents itself before we have had time to notice the difference between the sensation and the cause, as if to provide a basis for the intellect to draw conclusions. premise.

First, touch and vision have their own unique advantages; thus, they can help each other.Vision does not need to be touched, or even approached; its range is infinite, reaching as far as the planets.Moreover, sight is extraordinarily sensitive to even the faintest lights, shadows, colors, and transparencies; it therefore furnishes the intellect with a great deal of very determinate material, which, by working with practice, yields the shape, size, distance, and nature, and present them intuitively at the same time.Haptics, on the other hand, is undoubtedly inseparable from touch; the materials it offers are so diverse and believable that it is the most exploratory of all senses.Even intuition by sight cannot be separated from the sense of touch; moreover, sight may be regarded as a most imperfect sense of touch, which reaches far with light as long antennae; Among the properties of using light as an intermediary, it is one-sided and prone to deception; and the sense of touch can directly provide materials for recognizing size, shape, hardness, thickness, temperature, etc.The power of the sense of touch is partly due to the shape and mobility of our arms, hands, and fingers, and the intellect obtains the material for constructing objects in space according to where they are when they perceive them, and partly due to the power of muscles, which enable us to know An object's weight, strength, toughness, or fragility, all of which are seldom wrong.

However, these materials do not in any way produce intuitions, which are always a matter of the intellect.The sensation of pressing my hand on the table does not contain the appearance of a close connection between the elements within this object, or anything like it.It is only when perception goes from sensation to its cause that intellect constructs for itself a body with the properties of strength, impenetrability, and hardness.If, in the dark, I place my hand on a smooth surface, or grasp a ball about three inches in diameter, in both cases I feel a pressure in the same part of the hand; In this or another case, my intellect can construct the shape of the object, because the touch of the object is the cause of the sensation, as evidenced by my changing the position of the hand.The hand feeling of a person who is born blind is the same no matter which side or which direction it is on when perceiving a cubic object: although only a small part of the hand is pressed against the edge, the resulting sensation has no sense of three-dimensionality at all.From the resistance felt, however, his understanding draws an immediate and intuitive conclusion that this resistance must have a cause, and this cause is manifested by the conclusion that it is a solid body; by the movement of the arm To feel the object, if there is no change in the hand feeling, he can construct the three-dimensional shape of space, this ability is innate to him.If the causal and spatial representations, together with their laws, ceased to exist for him, the image of the cube would never arise from the continuous sensation in his hand.If a string is pulled through his hand, by reason of the friction he feels and the continual process of pulling the string, he can construct a long cylindrical object which always moves in one direction at a particular position on his hand .But the change of position in space by means of time, that is, the appearance of motion, can never arise from the mere sensation of his hand; for this sensation neither contains nor can produce anything of the kind by itself.On the contrary, it is the intellect which, prior to all experience, contains in itself the intuition of space and time, and of the possibility of motion with space and time; It's just a representation—asking for the cause of the feeling, and constructing the cause as an object with a certain shape and moving in a certain direction.For what a disparity there is between pure sensation in the hand and causal representation, substantiality, and movement in space in time!The feeling on the hand, even though the position and point of the touch is changed, the material it gives is always scarce, and it is not enough to construct a three-dimensional spatial representation from it, as well as extension, impenetrability, cohesion, The representation of the interplay between shape, solidity, softness, static and moving objects, in short, the basis of the objective world.On the contrary, all this is possible only because the intellect, which is prior to all experience, contains within itself space as the form of intuition; time as the form of change; and causality as the law governing its birth and death.It is precisely the pre-existence of all these forms prior to all experience that constitutes intellect.Physiologically, this is a function of the brain, just like the stomach is responsible for digestion, or the liver secretes bile, and this function is not learned through experience.Otherwise, it is impossible to explain why many born blind people can grasp a comprehensive and complete understanding of spatial relations, which enables them to compensate for the lack of vision to a large extent and achieve amazing success.Sanderson, for example, a hundred years ago, was born blind and taught optics, mathematics, and astronomy at Cambridge.This is the only way in which the diametrically opposed situation of Eva Lauco, who was born without arms and legs, acquired an intuition of the external world by sight alone, and no less slowly than other children.All this, therefore, proves that neither time nor space nor the laws of causality are acquired through touch and sight, nor are they anything foreign, but immanent, and thus non-empirical, which can originate only in the intellect.From this we can also know that the intuition of the material world is essentially a rational process, which is completed by the understanding, and the feeling only provides opportunities and materials for the use of reason in various specific situations.

-------- ① Diderot gave a detailed explanation to Sanderson in "Letters from the Blind". ② See "The World as Will and Representation", Volume Two, Chapter Four. I'm going to demonstrate that the same is true for vision.The only immediate material here is the sensation experienced by the retina.There are many variations of this feeling, but it boils down to light and darkness and the degrees in between, and then to colors.This feeling is entirely subjective: it exists only in our organism, under the skin.Without the intellect we could never be aware of these changes, which would have nothing in common with the shape, position, distance, or nearness of objects outside us, if our eyes had not made various special adjustments in the perception. place.For sight affords only a variety of influences upon the retina, just as a painter's palette is full of different pigments.If the intellect is suddenly deprived—for example, by cerebral palsy—which occurs for a split second while we are contemplating a magnificent expanse of nature, nothing remains in our consciousness, but the sensation does not change, because the It is the understanding that just now constructs the raw material of intuition.

Thus the intellect is able to produce the visible world out of such finite materials as light, shape, and colour, and, with the help of spatial intuition, through the simple function of tracing from effect to cause, the world can appear in various forms and infinite forms. Endless landscapes, and this depends first of all on the help of the sensation itself, which consists in the fact that the retina, as a spherical surface, can accommodate the juxtaposition of impressions; secondly, that light always moves in a straight line and is refracted in a straight line in the eye; finally , the retina has a direct ability to judge where the light rays imprinted on it come from, which may only be explained by the light rays passing through the spherical surface of the retina and entering behind it.From this, however, we learn that a mere impression immediately shows the direction of its cause; that is, it points directly in the direction of the light, or reflected light, to the position of the object.The transition to this object as cause undoubtedly presupposes the knowledge of causality and of the laws of space; but this knowledge constitutes precisely the content of the intellect, which in turn produces intuitions out of pure sensation.Now, let's examine the process by which it does so in more detail.

The first thing it does is to establish the impression of the object correctly, but the impression of the object is inverted on the retina.We know that the original inversion is produced in the following manner: since every point on the visible object is projected in every direction in a straight line, the rays from the uppermost cross the rays from the lowermost through the narrow aperture of the pupil. However, in this way, the former falls on the bottom and the latter on the top, and likewise, what comes from the right falls to the left, and what comes from the left falls to the right.The refractive organ of the eye, composed of aqueous fluid, crystal, and vitreous, serves only to concentrate the rays of light from objects so that they find a foothold in the confined space of the retina.If vision were only sensation, we should perceive the impression of an inverted object, because we receive it as such; comprehend something within.In fact, however, the understanding acts at once with its law of causality, and since it can obtain from the senses the data from which direction the light imprinted on the retina comes, it can go back along these two lines. Inquiry into its cause; so that this time the crossing of the rays takes place in the opposite direction, and the object as cause presents itself upright in space, i.e. the objects are in the position from which they first emitted the rays, and not in the position where they reached the retina superior. —The pure nature of the intellect in this process, which rules out all other, especially physiological, explanations, is also verified by the fact that if we put our head between our legs, or lie down on our On a hill, we still see the object upright and not upside down; although that part of the retina normally encounters the lower part of the object, it is now the higher part.In fact, if there is no intellect, everything will be chaotic.

The second thing the understanding does in converting sensations into intuitions is to produce a single intuition out of double sensations; Each is unique, independent of the impression received by the other eye; there is even a slight difference in direction, but the object presents itself in a single image.And this can only happen in the intellect, and the process is as follows: Unless we are looking at a very distant object, that is, 200 feet away, our eyes are never perfectly parallel.In addition, when we look at the object, they all aim directly at the object, so that the eyes of the two eyes converge on each other, so that the line of sight in each eye falls on an exact point on the object we are looking for. form an angle, which is called the viewing angle; the line of sight itself is called the boresight.When the object stands directly in front of us, these sight lines are printed exactly in the center of the retina, and there are two points which correspond exactly to each other in each eye.The understanding, whose sole task is to find the cause of all things, at once recognizes the impression as a point from something external, though the sensation is now double, and it ascribes this sensation to one cause, which, therefore, acts as a unitary cause. The object presents itself.Everything we perceive is perceived as a cause, that is, as the cause of an effect we have experienced, and thus in the understanding.However, because what we see with our eyes is not only a point, but also includes a rather large surface on the object, but we intuit it as a unified object, so it is necessary for us to explain it further .The rays from all the parts of the object on the side of the apex of the angle of view do not go directly to the center, but to the sides of the retina in each eye; the point of fall is the same on both sides.Let's take the left as an example.In this way, the points on which the rays strike are perfectly symmetrical to each other, including the center—in other words, they are the same point.The understanding at once comprehends them, and interprets them accordingly, using the above-mentioned laws of causal intuition; and consequently, not only the rays imprinted on the center of each retina, but all other correspondingly symmetrical rays falling on each retina, It comes down to a single point of light on the object being seen, that is, it sees both these individual points and the object as a whole.It is worth noting that in this process it is not the outer side of one retina that corresponds to the outer side of the other and the inner side with the other, but the right side of one retina is equal to the right side of the other, etc. ; So this kind of symmetry cannot be understood from physiology, but should be explained from geometry.A number of lucid accounts of this process, and of all the phenomena connected with it, are to be found in Robert Smith's Optics, and partly in Kestner's German translation (1755).I only present a diagram which, to be precise, represents a special case, to which we shall speak, but which may be used to illustrate the whole object, provided we abandon the point R without doubt.From this illustration, we can see that our eyes are constantly fixed on an object, so that corresponding symmetrical places on the two retinas receive light from the same point.When we look around by moving our eyes back and forth, right and left, up and down, the dot previously imprinted on the object at the center of each retina is now projected at a different position each time, but in any case the dot is in both eyes. The input position of is still left-to-left, right-to-right, and so on.In examining an object, the eye glides up and down so that every point on the object is continually brought into the center of the retina, where it is best seen: we see it fully with both eyes.It is therefore evident that seeing with only two eyes is in fact the same as touching an object with ten fingers, and that in different directions each eye and each finger makes a different impression: all these impressions are intellectual What is known from an object is, therefore, the intellect which knows and constructs the shape and size of the object in space.This is why a blind man can become a sculptor.We may take the famous example of Josef Kleinhaus, who died in Tyrol in 1853 and was a sculptor from the age of five.For whatever reason intuition acquires its material, intuition is always an operation of the understanding.

-------- ①Frankfurt "Tribune", July 22, 1853, introduced the sculptor as follows: - "Blind sculptor Joseph Kleinhaus, died in Naders, Tyrol on July 10. In his 5 At the age of 12, he was blinded by smallpox and has since consoled himself with sculpture. Prugg (Prugg) gave him guidance and provided him with models. At the age of 12, he sculpted a life-sized statue of Jesus. Fagan stayed in Nisir's studio for a short time. Due to his excellent quality and talent, he soon became a household name as a blind sculptor. His works are numerous and complete, and there are about 400 statues of Jesus made by him alone. , which is a testament to his proficiency, especially for a blind man. In addition, he has produced many other works, and just two months ago, he also shaped the Austrian Emperor Franz Joseph. bust, which has been sent to Vienna."

But if I touch the ball with my hands crossed, the same ball seems to me to be two—for my intellect, by the laws of space, leaves no doubt that the fingers are in their normal position and must produce The sensation of two hemispheres, since these two hemispheres touch the outer sides of the thumb and middle finger, and the intellect must have reasoned and constructed it as two spheres—and in terms of angle of view would also cause an object to appear to be two If our eyes did not focus their perspective symmetrically on and around a single point of the object, but each eye viewed it at a different oblique angle—in other words, if I looked sideways.For in this case the rays emanating from a certain point of this object do not impress symmetrically on corresponding symmetrical points of the retina, which our brain is accustomed to accept from experience, but fall on our eyes symmetrically. At other points quite different in position, on which only different bodies would have had such an influence; therefore I see two objects precisely because the intuition takes place through and in the understanding. of. — Even without squinting, this also happens, for example, when I fix my gaze on the farther of two objects placed in front of me at an unequal distance, and turn the angle of view completely towards it; for this When the light from the nearer object is not printed symmetrically on the corresponding position of the retina, the understanding sees them as two objects, that is, sees the nearer object as two.If, on the other hand, I turn my point of view completely to the nearer object and keep looking at it continuously, the farther object takes on a double character.It is easy to test our statement by holding a pencil two feet from our eyes and looking alternately at it and at another object behind it. But, the most wonderful thing is that this experiment can be done in reverse: when two real objects are placed very close to us, if we open our eyes very wide, we will see only one object.This is the most convincing proof that intuition is only the duty of the understanding, and is in any case not involved in the senses.Tie two cardboard tubes about 8 inches long and 1.5 inches in diameter parallel to each other like binoculars, and tie a shilling to the end of each tube.If we look into the tubes with our eyes from the other end, we can only see a tube around a shilling.For in this case the eyes see only perfectly parallel, and the rays from the coin are safely injected into the centers of the two retinas, and the points immediately surrounding them fall symmetrically to each other; therefore, The understanding must assume that, when objects are near, the position where the two axes of light usually converge allows only one object to be considered the cause of the reflected light.In other words, we see only one object; so in the understanding our apprehension of causality is immediate. Owing to the limitation of space, we cannot here refute the physiological explanation of the single vision; but we can suffice to see the fallacy of this explanation by the following consideration:— 1.If a single vision depends on organic connections, the corresponding points on the retina from which this phenomenon arises should be organically identical, but, as we have said, only in a geometrical sense. in this way.For organically speaking, the outer corners of a pair of eyes coincide with each other, the inner corners coincide with each other, and so do the other parts; but only the right side of the right retina coincides with the right side of the left retina, etc., to form a single vision. , which is irrefutably illustrated by the phenomena we have just described.Just because of the intellectual character of this process, only the most intelligent animals, such as mammals and birds of prey—especially owls—have eyes of this kind, so positioned that they align the two axes of vision in the same direction. a little. 2.The assumption, initiated by Newton, that the optic nerves converge or partially cross before entering the brain, is false.The reason is very simple, because if this is the case, it is impossible to see two images of an object by squinting.In addition, Vesares and Caesapinus have presented the anatomical case that the subject can only see a single object, even though the optic nerves do not converge or even touch.One of the chief pieces of evidence against the hypothesis that an impression is mixed rests on the fact that once the right eye is closed and the left is looking at the sun, the retention of a vivid image is always in the left eye and not in the right, and vice versa. -------- ①Newton's "Optics", the 15th question. The third process by which the understanding transforms sensation into intuition consists in its construction of objects out of the resulting simple surfaces—adding the third dimension of space.The intellect estimates the extension of objects in the third dimension of space through the law of causality—the second dimension of space is known innately by the intellect—that is, according to the degree to which the eyes are affected by objects and the gradual changes in light and dark.In fact, although objects are in three-dimensional space, they can only produce two-dimensional impressions in our eyes; because the nature of the organ of the eye is that our vision is only two-dimensional and not three-dimensional.The sense of three-dimensionality in intuition is produced by the understanding, whose only materials are where the eye gets its impressions, their limits, and the variations between light and dark: these materials directly show their cause, and make us distinguish what is before us. A disc is still a ball.This mental process, like the preceding ones, is so fleeting that we are only aware of its results.It is for this reason that perspective is so difficult to draw that it can only be solved mathematically and learned by training; although what drawing a perspective does is reproduce what the sight sees, which is the same as the provision of vision to the intellect as a third process. The material is the same: vision is only a flat expansion, and the intellect immediately adds a third dimension to the two dimensions of this expansion and the material described in it when it sees pictures and objects.In fact, perspective is as easy to read as printed material, but very few people can write it; the reason is that our intellect only grasps the effect that helps to find the cause when we visualize things. , as soon as the cause is found, the effect is immediately forgotten.For example, as soon as we see a chair, we immediately ignore its position; and describing the position of a chair belongs to the art of abstraction from the third process of the understanding, which is only to provide the observer with material for his own work. the process.As we have seen, if we look at it in the narrowest sense, it is an art of perspective painting; in a wider sense, it is the whole art of painting.A picture presents to us outlines according to the laws of perspective; light and dark play of light and shape;The observer sees and understands this by reducing similar causes to those to which they are accustomed.The art of painting consists in the conscious storage in memory of visual materials, what we call pre-third intellectual processes; Just put them aside, not retained in our memory.We now deepen our understanding of the intellectual character of the third process by illustrating a fourth process, which has an intrinsic connection with, and thus helps to explain, the third process. The fourth function of the understanding consists in gaining awareness of the distance between objects and us, and as such it constitutes the third dimension of space of which we have been speaking.As mentioned earlier, vision tells us the direction of the object, not the distance from us, that is, the position of the object.Therefore, only the understanding can discover this distance; or in other words, the distance is inferred purely from the measurement of causality.The most important thing here is vision, the angle to which the object is facing; however, the angle itself is ambiguous and tells nothing, just like a word with two meanings, which can only be understood in one sense from its relationship with the other. It can only be done in the connection of other meanings.面对同一个视角的客体，事实上它既可以离我们很近，也可以离我们很远，即可以很小，也可以很大；只有在我们预先确定了它的大小之后，才能通过视角知道它的距离。或者相反，通过已知的距离而确定其大小。直线透视以下列事实为基础：视角随距离增大而减小，其原则很容易在这里推出。我们的视力在各个方向的视程都是一样的，所以我们看实际存在的一切东西都仿佛是从凹陷的球面之内开始的，我们的眼睛就处于其中心位置。首先，无数个交叉的环由各个方向从球面中心穿过，由环划分测量出来的角都是可能的视角。其次，球面本身根据我们所给予它的半径的长度变更它的大小；因此，我们还可以把它设想为是由无数个同心的、透明的球面组成的。随着所有的半径向外分叉，这些同心球面就根据离开我们距离的远近而相应地变大，每一个切面环的度数也相应地增加，因此，客体的实际大小也就随着这种增大而增大。这样，客体的大小是根据它们在球面上所占居的相应部分的大小决定的——譬如说10°——无论这一客体占的10°是在直径2英里球面上，还是在直径10英尺的球面上，其视角保持不变，所以可以不予考虑。相反，假如客体的大小已经确定，它所占据的度数将随我们作为参数的球面的扩大和距离的延伸而按比例减少，它的整个轮廓将以类似的比例缩小。由此我们就得出了整个透视的基本法则；因为，客体以及客体之间的间隔必然会随着客体与我们之间的距离的增大而按比例地缩小，它们的整个轮廓也会因此缩小，其结果是：距离越远，在我们上面的客体就降，在我们下面的客体就升，而周围的一切客体将一起向中心靠拢。只要我们眼前所看到的可见的、相互联系的客体的继起是不间断的，这种渐近的集中和直线式的透视就能使我们对距离作出估计；但我们仅靠视角还不能做到这一点，因为知性在这里还需要其它材料的帮助，在一定意义上，我们需要通过距离更加精确地表明这个角的大小，以便对于这一视角作出说明。这类材料主要有四种，我打算具体地加以说明。由于有了这些材料，即使没有直线透视的帮助，对于一个站在200英尺开外的人，较之站在仅2英尺远的人，所对视角要小24倍，但在大多数情况下，我仍然能正确估计出他的身材。所有这些情况再一次说明直观不仅是感觉的事情，而且也是理智的事情。 ——我要在这里补充一个特别有趣的事实，进一步证实我已谈到过的直线透视的基础以及整个直观的理智特性。当我不断凝视轮廓鲜明的有色客体时，——譬如说红色十字架——当它长到足以引起生理联想，致使我的眼睛里出现的是一个绿色十字架，我的目光所投的面越远，它就显得越大，反之亦同。因为联想本身在我的视网膜中所占的那一部分是不变的，即最初受到红色十字架影响的那一部分；因此当它被认为是外在的，或换言之，被看作为是外在客体的结果时，它就形成一个不变的视角，譬如说2°。在这种情况下，假如没有对视角作任何说明，就把它移到远处的一个面上，这样，我必然会把它看作为是一个结果，十字架就会在远处从而是一个较大的球面上占据2°，因此它就显得大了。另一方面，假如我把联想投在一个较近的客体上，它将占据一个较小的球面的2°，因此它就小了。在这两种情况下，所产生的直观完全是客观的，很像是对外部客体的直观；由于它完全由主观的原因而生（从以一种完全不同的方式被引起的联想），因而证实了整个客观的直观的理智特征。 ——这一现象（我清楚地记得它第一次被我注意是在1815年）构成了塞根的一篇论文的主题，这篇论文1858年8月2日在《报告》上出版。这一现象在该文中被当作一个新发现，但被各类荒谬的解释歪曲了。那些著名的同行先生们决不放过堆积实验的机会，问题越复杂越好。经验是他们的格言；然而，就对所观察到的现象进行真实、合理的反映而言，那真是凤毛麟角，少而又少！ “经验！”“经验！”，蠢才们跟着随声附和。 现在我们转回到用以说明一定视觉的辅助材料上，其中我们首先发现的是眼睛内部的变化，眼睛借助于这些变化使折射器官通过增大或减少折射而适应不同的距离。这些变化是由什么构成的，现在尚未清楚地加以确定。凸状体曾经是探索的对象，后来又探索过角膜和晶状体；但是最新理论在我看来应该是最有道理的，这一理论认为，看远外的东西时晶状体后移，看近处时则前移。在后一种情况下，侧面的压力使它更加突出；以致这一过程同看歌剧时用的望远镜没什么两样。然而，刻卜勒已经把这一理论的主要内容表述过了，这一理论在许克的小册子《晶体的运动》中可以看到。即使我们没有清楚地意识到眼睛内部的这些变化，无论如何也应该感觉到，并且由此来估算距离。这些变化的有效范围大约从7英寸到16英尺这个距离内，对于此范围之外的清晰视觉，这些变化并不发生，因此，知性只能在这一范围内运用这些材料。 不过，超出这一范围，另外一种材料就可以使用了：由两个光轴形成的视角，我们在谈到单一视觉时曾对光轴有过解释。很显然，客体越远，视角就越小，反之亦然。就知性利用感觉提供的材料直观地估算距离而言，两眼相互之间的不同方向，必然会产生一种我们能够意识到的细微感觉。我们不仅可以利用这一材料认识距离，而且还可以利用眼睛的视差认识所看的客体的具体位置，所谓视差也就是在双眼看客体时方向上的细微不同；所以，如果我们闭上一只眼睛，就会感到客体似乎在动。因此，闭上一只眼睛就不易吹灭一支蜡柱，因为缺乏这种材料。但是，由于眼睛在客体的距离达到或超过200英尺时视线就开始平行，因而视角不再存在，因此这种材料只对说过的距离以内有效。 即使超出这种距离，知性还可以通过对大气层的透视估算距离，因为所有暗色客体前都笼罩着天蓝色，距离越远，各种色彩的模糊程度就越大（根据歌德完全正确和切实的色彩理论），而且所有的轮廓也越来越模糊。在意大利，大气层具有很高的透明度，这种材料就失去了效力，且很容易导致错误，例如，我们从弗拉斯卡蒂看提沃里时，提沃里就显得很近。另一方面，在雾中所有的客体都显得很大，这种材料就是反常的、夸大的；因为我们的知性假定了它们并非离我们这么近。 最后，还可以通过中介客体的大小（为我们直观所认识了的），比如田野、树林、河流等等来估算距离。这种估算方式只适于事物没有间断的情况，换言之，只适用于陆地而非天上的客体。而且，在平面与垂直这两种情况下，相对而言前者比后者用得多：200英尺高的塔顶上放一个球较之放在200英尺远的平面上看起来要小得多；因为，在后一种情况下，对于距离的估算更加精确。以这种方式看人，由于在他们与我们之间有很多东西潜藏在我们的视觉中不起作用，所以人总是显得很小。 我们的知性假设，相对于垂直方向而言，平面方向所直观到的东西越远也就越大。这样一个假定的事实之所以成立，部分原因是由于我们是用最后一种方式来估算距离的，因为这种方式对水平方向和地球上的客体是有效的；部分原因还由于我们是用大气层的透视来估算距离的，这种透视处在相类似的条件下。这就是为什么月亮在地平线上之所以比在天顶上显得要大得多的原因，虽然它的视角可以精确地测量出来——月亮印在眼睛里的印象——实际上视角在一种情况中并不比在另一种情况中大；这也可以用来说明穹形天空为什么看起来似乎是平面的原因，就是说，为什么它看起来平面延伸大于垂直延伸。因此，这两种情况都纯粹是理智的或大脑的，而非视觉的。假如有人提出反对意见说，月亮即使在天顶时偶尔也显得朦胧，但看上去并不见得显得大了一些，我们回答说：它也没有像在地平线时那样带有一些红色呀；因为这种朦胧是由于密度较大的水蒸汽造成的，因而与大气透视所说的朦胧不同。对此我可以把已经阐释过的再说一遍：这种估算距离的方式只适用于水平方向，而非垂直方向；另外，在这种情况中，其他的矫正措施也可以起作用。索热尔的一个经历与我们所谈的问题有关：他在勃朗峰时看到一个硕大的月亮正在升起，大的他竟认不出这是什么，结果被吓昏了。 另一方面，望远镜和放大镜的性质，取决于仅仅根据视角单独作出判断，即由距离判断大小、由大小判断距离；因为这里不包括其它四种估算距离的辅助手段。事实上，望远镜放大客体，但看来好像把它拉近了；因为我们凭经验已经知道它们的大小，因此我们这里是通过它们离我们的距离在缩短而说明它表面上变大的原因。例如，在望远镜里看到一幢房子，似乎房子被拉近了十倍，当然不是较之用肉眼看大了十倍。相反，放大镜并不是真正地放大，而不过是把客体与我们眼睛之间拉得近一些，这在其它情况下是办不到的；所以客体所显示的大小，跟不用放大镜时处于被拉近的位置上时的大小是一致的。事实上，由于我们眼睛的晶状体和角膜的凸起不足，在客体离我们眼睛的距离不到8至10英寸的情况下，我们就完全看不清客体；但是，如果我们用放大镜的凸面代替眼睛晶状体和角膜的凸面以增加光线折射，那么即使客体离我们的眼睛似乎只有半英寸的距离，我们也能获得客体清晰的图像。这样看到的客体离我们很近，其大小又与该距离相应，于是客体被知性转化为适合于我们很自然地看清客体的距离，即离我们的眼睛约8～10英寸，这样，我们就可以根据这一距离和给定的视角决定客体的大小。 我已详尽地阐明了视觉得以完成的所有不同的过程，这是为了更清楚、更无可非议地表明在这些过程中起决定作用的是知性。知性以空间和时间之基本的先天直观为基础，只从感觉中获得材料，然后通过把每一个变化构想为结果并进而由果求因，产生了客观世界的大脑现象。而且，知性要产生这种效果只能通过它自身的形式：因果律；因此，这是非常直接地、直观地完成的，并不借助于反思——通过概念和语言而来的抽象认识，这种抽象认识是第二类认识，即思维，因而是理性的材料。 毋庸理性参与而经过知性产生的这种认识甚至通过下面的事实即可表明：无论什么时候，当知性从一个给定的结果找到一个错误的原因时，而且确实认定就是这个原因，因此产生假象。我们的理性在抽象认识中无论把问题的真实情况看得多么清楚，都无法对知性有所帮助，尽管对原因的认识是错误的，假象却不受影响，仍然继续下去。上面提到的视觉和触觉产生双重表象的现象，是由于触觉和视觉的错位造成的，这种现象即可作为例子用来说明此类假象；同样，初生的月亮显得较大；在凹面镜的焦点上形成的图像却酷似空中漂浮的坚实物体；我们认为是真的，其实是着色的浮雕；假如一艘船碰巧沿着堤岸或从桥下驶过，我们站在堤岸或桥上似乎觉得很明显地在动；由于峰顶周围的空气极其纯净，因而就没有大气透视现象，高耸入云的山峦就显得很近。在这些以及与之相似的大量事例中，知性必然认为存在着一个它很熟悉且能够立即直观到的惯常的原因，虽然我们的理性已经以不同的途径达到了真理；因为知性认识先于理性认识，理智得不到理性的指导，因而假象——知性的蒙蔽——仍然不可改变；尽管错误——理性的蒙蔽——被排除。——被知性正确认识的是实在；被理性正确认识的是真理，换言之，是一个拥有充足根据的判断；假象（直观错误）与实在相对，错误（思维错误）与真理相对。 经验直观的纯粹形式部分——空间、时间和因果律——先天地被包含在理智之中；但是，这些形式对于经验材料的运用却不是先天的，而是由知性通过实践和经验获得经验材料。因此，新生婴儿虽然无疑地能够感受到光和色彩，但从严格的意义上来讲，它们还不能理解客体。他们出生后的最初几周毋宁说是在昏睡状态中度过的，此后，当他们的知性开始把自身的功能应用于由感觉提供的材料，特别是由触觉和视觉提供的材料时，他们才逐渐清醒，由此逐渐获得对于客体世界的意识。这种新生的意识，通过观察他们的眼睛所显示出来的日益增长的理解力以及他们的活动所表现出的一定程度的意图，特别是认出照顾他们的大人时所表现出的第一次微笑，我们可以清楚地认识到。甚至还可以观察到，他们一度用视觉和触觉来进行实验，以完善他们对在不同的光线下，不同方向上和不同距离外的客体的理解力：就这样默默地但却是认真地不断学习，直到他们成功地掌握我们已经描述过的关于视角的一切理智运用。后来动过手术的天生育人的情况更能说明存在着这一学习过程，因为他们能够陈述自己的印象，切塞尔顿①的盲人所提供的不是一个孤立的事例，我们还可从一切类似的事例中证实这么一个事实：天生的盲人在复明手术完成之后因得到视觉，无疑能够看到光亮、轮廓和色彩，但是直到知性学会把它的因果律运用于对知性来说是新的材料和变化中时，他们才有客体的客观直观。切塞尔顿的盲人在复明后第一次看到他的房间以及房内的各种客体时，仍然不能区别事物，而只是接受到所有片段的混成一体的总体印象，他把这一总体看作为一个斑驳多彩的光滑表面，而绝没有想到去认识以不同距离、前后分置的许多独立的客体。对于这类盲人来说，他们已经通过触觉认识了客体，但现在就要借助于触觉来引进视觉。开始，病人丝毫不解何为距离，而是用来乱抓。有个病人，当第一次从外面看到自己的房子时，想象不出看起来如此小的东西居然可以容纳如此多的房间。另一个病人在手术后的几个星期高兴地发现，在他的房间的墙壁上悬挂着的雕刻展现出了各种各样的客体。1817年10月23日的《晨报》上有一篇文章报道了一个生来就盲的年轻人，在他17岁时才获得视觉，他不得不学习理智直观，因为他第一次看到过去通过触觉认识了的客体时，甚至都不认识。每一客体不得不通过触觉引进到视觉中。至于他看到的客体的距离，他没有一点正确的判断，而是不论远近，一概用手去抓。——弗朗兹对此有下列表述②：—— “距离、形态和体积的确定观念，只有通过视觉和触觉，并对由这两种感觉所产生的印象加以反思而获得；但是，要达到这一目的，我们就必须考虑到肌肉的运动和个体的随意移动。——卡斯帕·豪泽在这方面对自身的经验所作的详尽的说明中指出，当他刚从禁锢中解脱出来时，他无论何时透过窗子看外面的客体，譬如街道、花园等，对他来说仿佛有一个离他的眼睛很近的百叶窗，上面杂乱无章地涂着各种颜色，其中的任何一件东西，他都不能加以认识和区分。他进而说道，直到他走出门坎，过了一段时间才使自己相信在一开始即出现在他眼睛之前的杂色百叶窗，以及许多其他客体，实际上是一些很不相同的事物；最后，百叶窗消失，之后他看到并且以适当的比例认识到各种事物。若干年后通过手术才获得视角的盲人，有时想象着所有的客体都触及他们的眼睛，而且客体离他们的距离近得使他们担心会伤着眼睛；有时他们跳向月亮，以为能抓住它；有时它们跟在飞逝于天空中的云后奔跑，要抓住它们，或者做另外一些此类的荒唐活动。由于这些观念是通过反思感觉而得来的，在任何情况下，思维在运作过程中不受损失和干扰就更为必要了，因为这样才能从视觉中形成对于客体的正确观念。我们可以提供一个由哈斯拉姆③给出的与之相关的例子说明这个问题：一个男孩视觉并没有毛病，但由于缺乏知性，在7岁时尚不能察知客体的距离，更不说是高度了；他经常把手伸向天花板的钉子，或者伸向月亮，要抓住它。因此，只有判断才能纠正、澄清这种观念，或者对于可见客体的直观。” -------- ①参见与本事例有关的《哲学学报》第35期中的原文。 ②弗朗兹：《眼睛，一篇关于保持这一器官健康以及改进视力的论文》，1839年，伦敦，丘吉尔出版社版，第34～36页。 ③哈斯拉姆（Haslam）：《关于疯狂和忧郁症的观察》第二版，第192页。