故城的春天看树，远处朦胧新绿，烟雨濛濛。新城的春天听鸟，后院短唱低鸣，下雪如雨。

费明: 读那些世界上人人传诵的脍炙人口的经典：87版《红楼梦》36集，每集45分钟，共计1620分钟，有名有姓的人物同样有六十多口子，在177分钟的《教父》影片风靡的上百个国家中，有几个国家曾上演悲金悼玉的红楼梦？

  • 老杨说红楼

  • 《父亲的草原母亲的河》听了不下百遍，常常听的泪流满面。为云飞的歌喉，为席慕容的乡情。更为了不起的神来之笔“河水在传唱着祖先的祝福，保佑漂泊的孩子找到回家的路。”

Dan Robinson Oxford Lectures on Kant’s first critique of pure reason

What is the question? The question is, how far our knowledge can reach? The extent to which we can rely on our senses, and the extent to which we can rely on reason.

Kant recognizes that the ultimate arbiter in matters of this kind has always been human rationality, but no one has taken the time to test the measuring instrument. That is, if the gold standard for whether an argument succeeds or not is rationality itself, one has to assess the instrument. How good a thermometer is it?

What does its nature bring to the table, as it sets about to make judgments about its own productions? And Kant, I think, is quite original in that regard. He understands that the senses and reason are both limited, but limited how.

  • ontology and epistemology

And there are fundamental ontological questions, and in fact, Aristotle’s metaphysics addresses questions of that sort. Are there really substances? Do they undergo change?

If they undergo change, do they remain the substance? They won’t, et cetera, et cetera. But of course, to address a question like that, you have to have some mode of inquiry.

And every mode of inquiry is subject to criticism. Every mode of inquiry has its limitations. And so in the process of addressing ontological questions, you also have to ask how adequate, how apt the mode of inquiry is that you’re using to address the question.

And that comes down to us as epistemology. And so metaphysics in the traditional sense was a combination of ontological and epistemological inquiry designed to answer fundamental questions about real existence and the nature of the relationships that obtain among really existing things. Sometimes Aristotle’s metaphysics has collapsed into, you can summarize his position by saying that the number of things we can know is determined by the number of questions we can ask, of which minimally, anyway, there are four.

Does a thing exist? If it exists, in what degree does it exist? In what relation does it stand to other things? And what is it for? What is it for? The teleological part of explanation.

What Kant wants to make clear is that the nature of this metaphysical inquiry is into those pure aspects of the understanding. And when Kant says pure, he always means non-empirical. Reinenfinnen, pure reason, is reason stripped of all empirical supports, attributes and content.

  • analytic and synthetic propositions

So what Aristotle offers then, by way of the syllogism, Kant is going to establish a nomenclature for him. This is where he makes the Kantian distinction between propositions that are analytic and propositions that are synthetic.

Analytic propositions are universally and necessarily true, but they’re true because Tartarus. In an analytic proposition, Kant says, the meaning of the subject term is contained in the meaning of the predicate term, as in all bachelors are unmarried men. Of course, it’s true that all bachelors are unmarried men, but it’s a definitional truth.

It’s not that you found out something new, either about bachelors or about unmarried men, by learning that all bachelors are unmarried men. So it’s in the nature of an analytic proposition that the truth it preserves can be known a priori. You don’t have to run around and ask people.

So analytic propositions are universal and universally and necessarily true, and their truth is known a priori, before experience, independently of experience. What about the facts of the world? The facts of the world are contained in what Kant refers to as synthetic propositions. Another one of those terms you wish had been translated in some other way. But synthetic in the sense of pulling together the attributes and properties of things such that you know what the thing is.

So, synthetic proposition. This contains both metal and glass. This is capable of owning a fluid. This is fluid. Now these synthetic propositions involve the pulling together of sensory data in such a way as to identify something. The typical claim is that the truth of synthetic propositions can only be established by experience.

So, the truth of any synthetic proposition is established a posteriori. In a nutshell, then, Hume’s claim, since Hume is always going to be in the background when he’s not in the foreground, Hume’s claim is that the truth of no synthetic proposition can be established a priori. Which is just another way of saying, reason cannot unearth the facts of the world by way of its own resources, do you see?

  • The insight is that we are not passive observers of the external world. We bring a certain assortment of cognitive and perceptual powers, themselves governed by principles, to bear on every factual claim we make. And thus it’s only by developing our understanding of our own mental apparatus. Now, he didn’t go so far as to say a thorough and critical appraisal of reason itself, but a development of our own mental apparatus so that we can see what it is we’re adding to what we take to be the truths of the external world.”

  • Evangelista Torricelli (1608-1647) Italian physicist and mathematician, the inventor of barometer.

  • Nature put Euclidean geometry in our heads as a convenient approximation to the real world and this is expressed in Kantian language as “geometry is synthetic a priori”.

All mathematical statements are a priori because they are capable of being confirmed without experience and synthetic because, at least sometimes, in examples like 1+1=2 the 2 is not contained in the 1 or the plus. Geometry is dependent upon the pure intuition of space, which was given a priori and was able to derive new concepts which gave it the synthetic distinction.

“Metaphysics rests on concepts alone—not, like mathematics, on their application to intuition.” Excerpt From: Norman Kemp Smith. “Immanuel Kant’s Critique of Pure Reason.” Macmillan and Co., Limited.

“Geometry is a science which determines the properties of space synthetically, and yet a priori. What, then, must be our representation of space, in order that such knowledge of it may be possible? It must in its origin be intuition; for from a mere concept no propositions can be obtained which go beyond the concept—as happens in geometry (Introduction, V).2 Further, this intuition must be a priori, that is, it must be found in us prior to any perception of an object, and must therefore be pure, not empirical, intuition. For geometrical propositions are one and all apodeictic, that is, are bound up with the consciousness of their necessity; for instance, that space has only three dimensions. Such propositions cannot be empirical or, in other words, judgments of experience, nor can they be derived from any such judgments (Introduction, II).” Excerpt From: Norman Kemp Smith. “Immanuel Kant’s Critique of Pure Reason.” Macmillan and Co., Limited.

We can deduce non-euclidean geometries from postulates but we cannot visualize them. Therefore what is a priori is still Euclidean geometry. We evolved to perceive reality in an Euclidean space. It could be an approximation to reality or not, that is beside the point. Possibility of non-euclidean geometries in paper, (in the form of deductions not visualizations) doesn’t mean that a human brain doesn’t necessarily experience the world in an Euclidean space, and cannot do so any other way even when he is dreaming. This has to do with the history of evolution and what we Needed to Know to get by.

Kant’s arguments are essentially meant to suggest that if you hold that Euclidean geometry is a body of a priori knowledge, then you have good reason to think that space (as the object of geometry) is somehow dependent on the human mind. This is not to say that Kant’s theory of geometry, and, more specifically, his view that the propositions of Euclidean geometry are synthetic (rather than analytic) a priori judgements was not novel. Math ‘falsified’ this view with the introduction of non-Euclidean geometry, which, it would seem, offers a better description of the structure of space than Euclidean geometry does.

So Bertrand Russell worked with his colleague Whitehead to try to derive math from logic in their Principia Mathematica but the entire project was declared impossible with Kurt Godel’s Incompleteness theorems.

Dan Robinson: the philosophical context for Kant’s Critique of Rure Reason

  • So you cannot use Aristotelian logic as a mode of discovery. You can use it as a truth preserving device. In fact, when we get to the Antinomies of Pure Reason, you will see what happens when you attempt to use multiple forms, not merely as a method, but as a mode of discovery. And of course, you end up discovering all sorts of things, all of them, all of them illusory.

  • Why should anyone assume that the objective sciences are themselves able to capture the order of nature, the lawfulness of nature? Kant begins with the assumption that nature is an orderly enterprise, that it is law-governed to be. On the strength of what does he say that? Well, on the strength of Newtonian science, the laws have been worked out. Well, from the fact that nature is lawful, and from the fact that we have uncovered the lawfulness of nature, we must have some means by which to overcome subjectivity and reach an objective knowledge of the way things are.

  • The very laws of the objective sciences show the sciences to have a rational character. Now that lawfulness is not given in the appearances. The stimulus that arrives at the organs of sense does not carry any information regarding lawfulness with it. If it’s visual, it’s just photons, do you see? If it’s auditory, it’s just air vibrations. So lawfulness must be coming from some place other than the arriving wave of stimulation. Our scientific understandings in which lawfulness is the defining feature, do find us relating to the objects of our understanding in one of two ways.

  • Either the cognition actually determines the concept itself by characteristic of mathematics, or in the natural sciences, it’s in some branches of the natural sciences, cognitively we actually can discover things that heretofore had not been. The first form of the relationship between cognition and its objects is what Kant says is the ground of all theoretical sciences, of which mathematics and physics are the two that are most developed. But they differ in misrespect. In mathematics, all of the concepts are a priori. In physics, some of the concepts arise from other sources, such as direct observation.

  • What does he mean when he says that all of the concepts in mathematics are a priori? I think it’s fair to say contemporary mathematicians probably would not accept that. But absolute pure intuitions of time and space, Kant wants to argue, you could have neither arithmetic nor geometry for it. Because all arithmetic operations are sequential, and sequentiality presupposes time. And time is a pure intuition. It’s not something given in the stimulus. So were it not for our spatiotemporal mode of apprehension, we would be in a position for neither arithmetic operations nor geometric operations. Geometry presupposes just that spatial context that is provided by the pure intuition of space, as arithmetic, as the pure intuition of time, provides the means by which arithmetic sequential operations become possible. I’m not defending this. I’m attempting to clarify. Arithmetic requires the pure intuition of time, because it depends on succession. And geometry comparably depends on space.

  • What Newton and Galileo realized is that reason only perceives that which it produces after its own design. You see, you’d have no way of launching the project of physics on entirely a posteriori grounds. You already have a conceptual framework of lawfulness, orderliness, causality, etc. To put the ball in play. As Kant says, accidental observations, accidental observations made according to no preconceived plan, could not be united under a necessary law. But it is this that reason seeks for and requires. This is what reason is looking for when reason undertakes scientific inquiry. He goes on to say, it is only the principle of reason which can give to concordant phenomena, the validity of laws, and it is only an experiment directed by these rational principles that give them any real utility. And so the question is whether metaphysics can be developed along the same lines.

  • The important point is this. What Copernicus establishes is that the observer is not a passive recipient of things that just come in from the solar system. He is an active participant in his own observations, and his position and his velocity determine the model of reality that he will construct. That’s the main thing that Kant finds in Copernicus.

Boris Cherny: creator of Claude Code at Anthropic

Peter Steinberger: creator of Openclaw

rust music visualization

current AI

Bixonimania: fake disease to fool AI 2024 created 2026 appeared. the story was reported at Nature on April 07, 2026..

Simon Willison, software engineer in the age of AI: No matter how good these things get, they will still need someone to find problems for them to solve, define those problems and confirm that they are solved.

Alex Woods: The goal of writing is not to have written. It is to have increased your understanding, and then the understanding of those around you. The second order goal of writing is to become more capable. It is like working out. Every time you do a rep on the boundary of what you can do, you get stronger. It is uncomfortable and effortful. Letting an LLM write for you is like paying somebody to work out for you.