A Treatise of Human Nature

All the perceptions of the human mind resolve themselves into two distinct kinds, which I shall call IMPRESSIONS and IDEAS. The difference betwixt these consists in the degrees of force and liveliness, with which they strike upon the mind.

开篇即以清楚区分（印象=强烈生动，观念=微弱摹本）奠定全书术语基础；休谟的文体清楚从容，读者可步步跟随，故清晰度为 82。

(休谟论证) 我们没有"必然联系"的印象——我们只能观察到事件的恒常会合（constant conjunction），因果必然性是心灵的习惯联想，而非对象本身的性质。

因果分析作为哲学批判（揭示必然性的心理起源）在思想史上无可撼动；但作为经验心理学，其联想主义机制已被现代认知科学超越，故准确性为 85。

(副标题) An Attempt to Introduce the Experimental Method of Reasoning into Moral Subjects (尝试把实验推理方法引入道德主题) — Book I Of the Understanding / Book II Of the Passions / Book III Of Morals.

三卷架构（知性→情感→道德）清楚且副标题即方法论宣言；但 Book I 内部（本体论+空间时间+因果+怀疑论）偶有枝蔓，年轻时的休谟论证冗长，故结构为 85。

(休谟以台球碰撞说明因果：白球撞红球，我们看到的只是先后与接触，看不到"使红球动"的力——必然性是观察多次后的心灵习惯)

例证是精巧的思想实验（台球、缺席的朋友、砸碎的花瓶），服务于概念分析而非经验归纳；抽象但有效，只是"实验方法"的承诺与例证的经验密度有落差，故例证为 75。

Reason is, and ought only to be the slave of the passions, and can never pretend to any other office than to serve and obey them.

"理性是且只应是激情的奴隶"——这是理解人类动机的根本工具：不要问"他为什么不理性"，要问"理性在为哪个激情服务"；对心理咨询、行为设计、伦理决策是持久的分析框架，故实用性为 70。

In every system of morality, which I have hitherto met with, I have always remark'd, that the author proceeds for some time in the ordinary way of reasoning... when of a sudden I am surpriz'd to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not... a reason should be given, for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it.

"是"与"应当"的鸿沟——从事实命题无法逻辑推出价值命题——至今是元伦理学的核心问题；休谟在一段脚注式的观察中开辟了整个子领域，故深度为 96。

(休谟的归纳问题：我们用过去推断未来，但这个推断本身无法用经验或理性证明——Pearl 的因果推断、Haidt 的道德直觉、Damasio 的情感神经科学都在与休谟对话)

因果推断（Pearl 的 do-calculus）、道德心理学（Haidt 的社会直觉主义）、情感与理性（Damasio）、机器学习的归纳问题——休谟 1739 年的怀疑仍是 2026 年的前沿，故时效性为 90。

The intense view of these manifold contradictions and imperfections in human reason has so wrought upon me, and heated my brain, that I am ready to reject all belief and reasoning, and can look upon no opinion even as more probable or likely than another... I dine, I play a game of back-gammon, I converse, and am merry with my friends; and when after three or four hours' amusement, I wou'd return to these speculations, they appear so cold, and strain'd, and ridiculous, that I cannot find in my heart to enter into them any farther.

怀疑论危机后的"晚餐、双陆棋、与朋友谈笑"——哲学史上最有人味的段落之一：休谟用生活的自然疗法治愈哲学的过度思辨，文体从容、机锋、自反，故文笔为 88。

(对洛克、贝克莱、霍布斯、Shaftesbury、Hutcheson 的继承与批评多在正文暗示，无脚注标注)

无学术引用体系，思想交锋凭正文暗示；1739 年体例如此，但按出处透明度维度须如实扣分，故出处透明度为 55。