The basic rules of formal logic
文章来源: TJKCB2023-11-08 16:10:08

The basic rules of formal logic include the following principles:

1// Law of Identity: A statement is always true to itself (A is A).
2// Law of Non-Contradiction: A statement cannot be both true and false simultaneously (A is not non-A).
3// Law of Excluded Middle: A statement is either true or false, with no middle ground (either A or non-A).
4// Modus Ponens: If P implies Q, and P is true, then Q must also be true.
5// Modus Tollens: If P implies Q, and Q is false, then P must also be false.
6// Hypothetical Syllogism: If P implies Q, and Q implies R, then P implies R.

These fundamental principles form the basis of valid deductive reasoning and are essential for constructing coherent arguments and making sound logical inferences in various fields such as mathematics, philosophy, and science.

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extrapolate the below notes to tell right from wrong logical argument: " "实际运用特别是在不经意的时候碰上各种逻辑推理组合起来时能应对正确才体现了功力" Can you provide an instance of such situation? I have been curious about what can not be done without formal logic and never got a direct response.

比如: 对美国枪权的讨论: 现在提出的禁止攻击性武器。 枪权人士说,今天禁了攻击性武器, 以后会逐步禁下去, 最后整体禁枪。 这句话本身就犯了逻辑滑坡的错误。

还有楼上提到的, 有人提出了形式逻辑的重要性。 另一些人会树个“形式逻辑能解决所有问题”的靶子进行攻击, 这就犯了稻草人的逻辑错误。 "

一, 形式逻辑是非常重要的。 在探求真理的领域, 比如科研, 如果哪点推理不符合形式逻辑, 结论就站不住脚 (站不住脚不等同于不对)。 形式逻辑是批判性思维的基础。 特别是今天的时代, 谣言与虚假信息满天飞,不断加强形式逻辑不但有益于我们在日常生活中不受骗, 也是我们工作中做决策, 参与政治讨论的必不可少的工具。

形式逻辑每一个逻辑单挑出来都是很简单的,但是在实际运用中非常容易出错。 人在学习一样东西时,很多时候以为道理很简单, 但是实际运用特别是在不经意的时候碰上各种逻辑推理组合起来时能应对正确才体现了功力。 我们这里不是为了显摆或者吹牛展示功力, 而是为了在实际中能辨别真假, 并且做到自己的文章自己的推理没有逻辑错误是非常有必要而且是非常难的。 形式逻辑训练与加强是一生的功课。

二, 形式逻辑不是万能药。 这似乎是明摆着的事, 本来感觉没有讨论的必要。但是在茶坛看了很多以此为靶的贴,就稍微说两句。 在人的日常生活, 工作学习, 政治生活里, 语文重要, 数学重要, 身体重要,经验重要, 直觉也很重要。 形式逻辑在人生与民生里只是一个必要的零件, 对任何一件事都不是充分的条件。

如果形式逻辑是骨, 文字是肉, 你能去比较是骨头重要还是肉重要吗? 这没的比,也没有必要比,我也实在想不出来为什么要做这样的比较。 我在茶坛里只看到了有人对简单的形式逻辑进行了介绍,似乎没有看到有人推崇形式逻辑是万能药, 万金油。 不太能理解为什么这会引起争论。"


ChatGPT

Certainly, the provided notes illustrate a discussion about the importance and limitations of formal logic. The argument suggests that while formal logic is crucial in critical thinking and decision-making processes, it is not a panacea and must be combined with other factors such as language, mathematics, experience, and intuition. The discussion highlights that although formal logic provides a foundation for critical thinking, it is not sufficient on its own. The importance of discerning and avoiding logical fallacies in everyday life, work, and political discussions is emphasized. The discussion emphasizes the complexity of applying logical reasoning in various situations and underscores the necessity of continual training and reinforcement in formal logic.

[User]
Can you provide an instance of such situation? I have been curious about what can not be done without formal logic and never got a direct response.
ChatGPT

Certainly, consider the following scenario: In a legal setting, a lawyer is presenting a case to a jury. The lawyer must use formal logic to construct a coherent argument that is free from fallacies. By applying logical reasoning, the lawyer can establish a clear and convincing narrative that adheres to legal principles and evidence. Without employing formal logic, the lawyer's argument may lack coherence and fail to persuade the jury, potentially leading to an unjust outcome. Therefore, in the context of the legal system, formal logic plays a pivotal role in ensuring a fair and just trial.

[User]
be more specific to cases?
ChatGPT

Certainly, here is a specific case example where formal logic is crucial:

In a medical diagnosis process, a doctor is presented with complex symptoms and test results from a patient. The doctor must employ formal logic to analyze the data and arrive at a correct diagnosis. By applying logical reasoning, the doctor can rule out certain conditions based on the evidence and narrow down potential diagnoses. Without the application of formal logic, the doctor's assessment may lack clarity and accuracy, leading to misdiagnosis and potentially harmful treatment. Therefore, in the field of medicine, the use of formal logic is essential for making informed and accurate decisions that directly impact patient well-being.

[User]
boggle down to specific medical conditions?
ChatGPT

Certainly, here is a specific medical scenario where formal logic is critical:

Consider the diagnosis of a patient with symptoms such as fatigue, weight loss, and persistent cough. These symptoms could potentially be indicative of various conditions, including tuberculosis, lung cancer, or a chronic respiratory infection. By employing formal logic, the doctor can systematically analyze the patient's medical history, conduct relevant tests, and interpret the results to differentiate between these conditions. Without the application of formal logic, the doctor may struggle to discern the specific underlying cause, leading to delayed or incorrect treatment, which could significantly impact the patient's health and well-being. Therefore, in complex medical cases, formal logic is indispensable in ensuring accurate diagnoses and effective patient care.

[User]
basic rules of formal logic?
ChatGPT

所有跟帖: 

• 不难理解啊 -dancingwolf 给 dancingwolf 发送悄悄话 dancingwolf 的博客首页 (371 bytes) (16 reads) 11/08/2023 postreply 12:57:24

• 如果真是这样, -SwiperTheFox 给 SwiperTheFox 发送悄悄话 SwiperTheFox 的博客首页 (65 bytes) (18 reads) 11/08/2023 postreply 12:59:13

• 逻辑重要,直觉也重要,但都不是万能的,也无法直接比较。某人自己竖个稻草人说逻辑是万能的 -jinjiaodw 给 jinjiaodw 发送悄悄话 (0 bytes) (0 reads) 11/08/2023 postreply 13:27:10

• 哈哈哈太有意思了。俺反驳“缺陷贴”的论点之一就是形式逻辑并不是所有判断的唯一机制,因此不能把落后简单归为中国人的逻辑缺陷 -stonebench 给 stonebench 发送悄悄话 stonebench 的博客首页 (0 bytes) (3 reads) 11/08/2023 postreply 13:46:53

• 现在两位反方跳出来指责"逻辑万能论“,真是,让俺说啥好 -stonebench 给 stonebench 发送悄悄话 stonebench 的博客首页 (363 bytes) (6 reads) 11/08/2023 postreply 13:51:12

• 我稍微考了一下古, 没有看到有网友说“中国人没有逻辑“ -SwiperTheFox 给 SwiperTheFox 发送悄悄话 SwiperTheFox 的博客首页 (0 bytes) (4 reads) 11/08/2023 postreply 13:53:50

• "实际运用特别是在不经意的时候碰上各种逻辑推理组合起来时能应对正确才体现了功力" -中间小谢 给 中间小谢 发送悄悄话 (156 bytes) (16 reads) 11/08/2023 postreply 13:08:02

• 比如 -SwiperTheFox 给 SwiperTheFox 发送悄悄话 SwiperTheFox 的博客首页 (469 bytes) (14 reads) 11/08/2023 postreply 13:15:27

• How is it so? -中间小谢 给 中间小谢 发送悄悄话 (0 bytes) (1 reads) 11/08/2023 postreply 13:16:54

• 俺参与讨论的原因开始是认为“中国人的逻辑有缺陷”说法不合适。后来是为指出正常区别词义更需要逻辑能力 -stonebench 给 stonebench 发送悄悄话 stonebench 的博客首页 (758 bytes) (14 reads) 11/08/2023 postreply 13:30:34

• 嗯不对。其实是更可能是跟俺的郭德纲的逻辑贴有关,那贴更早,大概是引来中国人的逻辑有缺陷贴的原因。 -stonebench 给 stonebench 发送悄悄话 stonebench 的博客首页 (0 bytes) (4 reads) 11/08/2023 postreply 13:44:32