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感知：对客观现实的构建

世间万物，是否存在一个客观的真相？客观真相，当然存在。世界如其所是，真实存在。

只不过，我们所见，并非全貌。森罗万象，我们永远无法窥其全貌。事实上，不求面面俱到，或许更有裨益。

因为，除了仰仗我们的感官，我们别无他法去直接触及这个物质世界。

然而，我们的感官时常会将现实世界的方方面面混为一谈，所以，我们永远无法确知我们的感知是否分毫不差。

问题的关键，与其说是我们是否看到了世界的真实面貌，不如说是我们是否真的能够准确地认识这个世界。答案是：不能，我们做不到。也许这听上去有悖常理，但如果我们把“眼见为实”理解为“所见即所及双眸之物”，那么我们可以“看到”的，其实远不止“所见”本身。

举个例子。假设我走进一个房间，墙上满是涂鸦，而这些涂鸦恰巧令我深感不适。我看着这些涂鸦，顿时面红耳赤，心跳加速，我感到愤怒，甚至震惊。试想，如果我不懂涂鸦所用的文字，尽管我的视网膜上可能会接收到完全相同的视觉信号，我的视觉神经初期也会产生同样的神经冲动，但我却未必会产生相同的情绪反应。

由此可见，我们所能感知到的，远远超出了投射到我们神经系统中的信息。

那么，现实究竟是否客观存在呢？

我们所感知到的味道、气味、颜色，其实都是我们感官的加工产物。它们并非客观现实的固有属性，而是我们感官的创造。

那么，究竟何谓客观现实呢？

我所说的客观现实，其实和大多数物理学家的定义是一致的，也就是说，如果一个事物不以人的感知为转移，能够独立存在，那么它就是客观真实的。

颜色、气味、味道等等，在这个层面上，都不能算是真正客观的存在。当然，它们在另一种意义上又是真实的，因为它们是真实存在的体验。

比如，你的头痛是一种真实存在的体验，尽管这种体验只有你才能感知。所以，它存在的形式，和物理学家所说的客观现实截然不同。

我们总是倾向于相信，我们的感官不会说谎。

所以当我意识到，不仅仅是味觉、嗅觉和颜色是我们感官的编造，而且并非客观真实时，我感到无比震惊。

不仅如此，甚至连时空本身，以及时空中的一切，比如各种物体、电子、夸克、太阳、月亮，它们的形状、质量、速度，所有这些物理属性，其实也都是某种人为的“设定”。

有时候，人们真的很难理解，我们的大脑接收到的信息其实是没什么意义的，因为当人们睁开眼睛，环顾四周，看到一切如常，就会想当然地认为一切尽收眼底，怎会毫无意义呢？

举个简单的例子，就拿颜色来说。关于光学的科学知识告诉我们，我们天生的感知能力其实错过了太多太多信息。人类对于颜色的感知，本质上是受限于量子力学原理的。

将人类对颜色的感知与对声音的感知进行比较，会非常有意思。

比如说，把两个纯音，比如 C 音和 G 音放在一起，组成一个简单的五度和弦。当你听到这个和弦的时候，即使它们是一起演奏的，你仍然可以分辨出这两个单独的音。你既能感知到和弦的整体效果，也能分辨出每个独立的音符。

然而，颜色就不同了。假设你把两种不同的颜色，比如光谱中的绿色和红色混合在一起，你看到的并不是一个可以分辨出原本独立颜色的组合，而是一种介于两者之间的混合色。事实上，你会看到一种类似于黄色的颜色。这就好比，在音乐中，当你同时弹奏 C 音和 G 音的时候，你听到的不是一个和弦，而只是一个 E 音，一个介于 C 音和 G 音之间的音符。

所以，从这个最基本的层面来说，我们甚至没有如实地反映出我们所接收到的信息，而之所以会这样，是因为这种选择性的反映方式对我们更有利。换句话说，我们感知到的，其实是信息对我们的“效用”，而不是信息本身。

自然选择的进化机制，塑造了我们感知世界的方式，而这种方式的最终目的是为了让我们更好地生存。

所以，如果我看到一条蛇，我就不会去捡起它。如果我看到悬崖，我就不会跳下去。如果我看到一列火车迎面驶来，我就不会站在铁轨上。

我们必须认真对待我们的感知，但这并不意味着我们可以完全按照字面意思去理解它们。

多元视角、科学方法与理论的价值

感知本身，或者说看待事物的视角，都是由感知行为决定的，而这种视角，本质上就是对事物原本信息的提炼和简化。

我对它的视角所获得的信息，将远远少于事物的全部信息。

我可以从东面观察一个物体，或者从西面，从上面，从北面，或者从内部，从微观的层面，或者借助望远镜，每一种观察方式都会给我带来不同的信息。但没有哪一种方式能够让我获取关于这个物体的全部信息。

因此，根本不存在一个全知全能的视角，能够让我们获得任何事物的所有信息。

这就意味着，现实本身是超越任何单一视角的。任何单一视角都无法涵盖它的全部。

所以，我们必须从多个视角来看待问题。每一个视角都能反映出部分的现实，捕捉到一些特定的信息。

当然，在这个过程中，也难免会产生信息的失真。

比如，我可能透过鱼眼镜头，或者有色眼镜来看事物，这就会造成一定程度的扭曲和失真。

那么，这一切又有什么意义呢？

它的意义在于，具备从多个视角看待问题的能力，认识到每个视角所反映的片面真相，然后能够将这些不同的视角整合成一个超越任何单一视角的、更全面的认知。

这种能力可以帮助我们更好地认识不同视角之间的联系，从而指导我们做出更明智的决策，这对于我们在这个纷繁复杂的世界中游刃有余至关重要。

那么，我们究竟如何才能做出关于真理的判断呢？我们又如何才能知道，我们所认为的真理是否经得起推敲呢？

这就要说到科学方法了。首先，我们要从观察入手，提出问题，然后构思出一个假设，这个假设应该能够解答我们提出的问题，接下来，我们要想办法去验证这个假设。这就是科学的方法，它可以用来解决各种各样的问题。

如今，有一种论调甚嚣尘上，企图否认客观真理的价值。然而，科学的基石正是对客观真理的信念，并且这种信念是行之有效的，工程学，以及基于客观真理的科学技术，都已经取得了丰硕的成果。

科学技术让人类的飞机翱翔于天际，将人类送上月球，还让人造的机器探测车登陆火星，甚至造访遥远的彗星。科学是有效的，科学帮助人类研制出了各种抗生素和疫苗。

所以，如果有人说：“噢，根本就没有什么客观真理，一切都是主观的，一切都是社会建构的”，你不妨把这番话拿去跟医生说，跟航天科学家说。事实已经充分证明，科学是有效的，而那种认为“客观真理不存在”的论调，根本就站不住脚。

当你写下一个理论的时候，这个理论本身就成了你的老师。从某种意义上说，它甚至比你还要“聪明”。

当年，爱因斯坦写下广义相对论的方程式时，他自己也未曾料到，这些方程式其实已经预言了黑洞的存在。从这个角度来看，这些方程式甚至比爱因斯坦本人还要“高明”。爱因斯坦本人在之后的几十年里，一直都不相信黑洞真的存在。尽管他的方程式已经非常明确地表明了黑洞存在的可能性，但爱因斯坦本人还是矢口否认。结果证明，爱因斯坦错了，而方程式是对的。

所以，这真的很有意思，我们之所以要建立这些理论，正是因为我们可以从中学到新的东西。

当你试图探究事物的本质时，你可能会发现，针对不同的问题，需要运用不同的方法，才能更好地理解其背后所隐藏的规律。

例如，在探索人类思维的过程中，如果想要从物理层面去理解大脑的运作机制，就需要运用到一种特定的方法。而且我们完全有理由相信，我们目前所掌握的基本物理定律，已经足以支持这种研究方式。

但是，如果想要进一步理解人类的行为模式，比如各种思维过程、情绪变化等等，是如何融汇成一个人的性格，进而影响一个人的行为的，这就需要用到截然不同的理解方式，也需要用完全不同的方法，才能更好地剖析其背后复杂的信息结构。

附件

Is there an external reality? Of course there's an external reality. The world exists. It's just that we don't see it as it is. We could never see it as it is. In fact, it's even useful to not see it as it is. And the reason is because we have no direct access to that physical world other than through our senses. And because our senses conflate multiple aspects of that world, we can never know whether our perceptions are in any way accurate. It's not so much do we see the world in the way that it really is, but do we actually even see it accurately? And the answer is no, we don't.

However paradoxical it sounds, if we think of what is visible, as just what projects to the eyes, we see much more than is visible. Let me give you an example. I walk into a room and there's graffiti on the wall, and imagine it's graffiti that I find really offensive. I look at it, I flush, my heart starts to race, I'm outraged, I'm taken aback. Of course, if I didn't know the language in which it was written, I could have had exactly the same retinal events and the same events in my early visual system without any corresponding reaction. Much more shows up for us than just what projects into our nervous system.

Is reality objective? Our senses are also making up the tastes, odors and colors that we experience. They're not properties of an objective reality, they're actually properties of our senses that they're fabricating. What is objective reality? By objective reality, I mean what most physicists would mean, and that is, that something is objectively real if it would continue to exist even if there were no creatures to perceive it. Colors, odors, tastes, and so on are not real in that sense of objective reality. They are real in a different sense, they're real experiences. Your headache is a real experience, even though it could not exist without you perceiving it. So, it exists in a different way than the objective reality that physicists talk about.

We always assume that our senses are telling us the truth. So it was quite a stunning shock to me when I realized it's not just tastes, odors and colors that are the fabrications of our senses and are not objectively real, space-time itself, and everything within space time, objects, electrons, quarks, the sun, the moon, their shapes, their masses, their velocities, all of these physical properties are also constructions.

Sometimes it's really difficult for people to understand that the data that your brain is receiving is meaningless, because when they open their eyes, they look around they say, well I see everything, what do you mean it's meaningless? A really simple example is color. Scientific knowledge of what light is, shows us that our natural perception leaves a lot on the table. The human perception of color is limited really by the principles of quantum mechanics. It's interesting to compare the human perception of color to the perception of sound. When you have two pure tones together, like a C and a G, a simple chord that's a fifth. If you hear that, you can hear the separate tones even though they're played together, and you hear a chord. You can also sense the separate tones, whereas with colors, if you have two different colors, say spectral green and spectral red, and mix them, what you see is not a chord where you can see the distinct identities preserved, but rather an intermediate color. In fact, you'll see something that looks like yellow. It's as if in music, when you play to C and a G together, instead of hearing a chord, you just heard the note E, the intermediate note.

So, at this most basic level, we don't represent even the information we're getting in any accurate way, and the reason is because it was useful to see it this way. So we're seeing the utility of the data, not the data. Evolution by natural selection has shaped us with perceptions that are designed to keep us alive. So if I see a snake, don't pick it up. If I see a cliff, don't jump off. If I see a train, don't step in front of it. We have to take our perceptions seriously, but that does not entitle us to take them literally.

Perception itself, a perspective on something defined by perception, is inherently a reduction of the information of the thing. My perspective of it is going to be a lot less total information than the actual thing is. I can look at the object from the east side, or the west side or the top or the north side, or the inside microscopically, telescopically, they'll all give me different information. None will give me the entirety of the information about the situation. So there is no all-encompassing perspective that gives me all of the information about almost any situation. What this means is that reality itself is trans perspectival. It can't be captured in any perspective. So multiple perspectives have to be taken. All of which will have some part of the reality, some signal. There may also be distortion. I may be looking at the thing through a fish-eye lens or through a colored lens, it creates some distortion.

Why does this matter? The ability to take multiple perspectives, to see the partial truth in them, and then to be able to seem them together into something that isn't a perspective. It's a trans perspective capacity to hold the relationships between many perspectives in a way that can inform our choice making is fundamental to navigating reality well.

How is it that we make claims of truth? And how would we begin to know if what we think is true is actually true? This is the beginning of the scientific method. Let us begin with observation, pose a question, figure out what the hypothesis would be that would answer a particular question, and then figure out how we would begin to address the hypothesis. That is a scientific approach to questions that could be addressed any number of ways.

There is a kind of whispering campaign against the value of objective truth. Science whose belief in objective truth works, engineering, technology based upon the science of objective truth achieves results. It manages to build planes that get off the ground. It manages to send people to the moon and explore Mars with robotic vehicles on comets. Science works, science produces antibiotics, vaccines that work. So anybody who chooses to say, oh there's no such thing as objective truth, it's all subjective, it's all socially constructed, tell that to a doctor, tell that to a space scientist. Manifestly, science works and the view that there is no such thing as objective truth doesn't.

When you write down the theory, the theory then becomes your teacher. It becomes smarter than you in a way. When Einstein wrote down the equations of general relativity he did not know that they entailed the existence of black holes. In that sense, the equations were smarter than Einstein. Einstein didn't believe in black holes for decades. The equations were very clear that they could exist. Einstein said no. It turned out Einstein was wrong, and the equations were right. So, it's very interesting, we do these theories because we can learn from them.

When you try to address the nature of things, you may find that asking different questions requires different ways of processing the underlying reality. For instance, in understanding the human mind, to understand it physically requires one kind of processing, and there's every reason to think that we already have fundamental physical laws that are adequate to that kind of treatment. But to understand how a person works, how thought processes, moods and so forth add up to a personality and a human actor will require quite different ways of understanding and quite different ways of processing the underlying information structure. Get smarter, faster, with new videos every week from the world's biggest thinkers.