# Essential vs. Accidental Properties

> 【EN】The terms ‘essential property’ and ‘accidental property’ have many distinct senses in philosophy. Two have figured prominently in analytic metaphysics of the last 70 years or so. There is the modal sense , according to which (at least as a first pass) an essential property of an object is a property that it must have while an accidental property of an object is a property that it happens to have but that it could lack. This use was dominant among analytic metaphysicians during the second half of the 20th Century. There is another sense, the whatness sense , according to which (at least as a first pass) an essential property of an object is one that provides an answer to the question of what the object is while an accidental property of the object does not provide such an answer. … 【中】词条梳理“本质属性”与“偶然属性”的诸种含义，重点考察模态意义与“是什么”意义（whatness）两脉：介绍形而上学的必然性与可能性、刻画模态本质主义的诸种方式、若干著名的模态本质主义主张，以及对它的怀疑；还讨论后天模态本质主张如何被认识、这类主张在非同一性论证中的作用，并给出理解 whatness 本质性的若干方案。

- ID: m13205
- Category: culture
- Domain: 哲学

## Definition

这一区分在哲学中有多种含义，近七十年分析形而上学中主要有两种。按模态意义，对象的本质属性是它必定具有的属性，偶然属性是它实际具有但可以缺乏的属性；这一用法在二十世纪下半叶占主导地位。 脚手架作用：- 锁定定义核心：剥离可变特征，找出缺了它该对象就不再是其自身的那个属性。 - 检验替换设想：设想某特征改变后对象是否仍是同一个，避免把偶性误当本质。

## How it works

借助形而上学的必然与可能：若某属性在该对象存在的所有可能世界中都为它所具有，该属性就是本质的；若可以设想它缺乏该属性而仍是同一个对象，则为偶然。跨世界同一性为判断提供依据。

## Practice

1) 指明讨论的是哪一个对象；2) 提出候选属性；3) 尝试构造它在其中缺乏该属性却仍是自身的可能世界；4) 若设想不出来，则倾向判为本质属性；5) 注意区分模态意义与 whatness 意义，别混用两套标准。

## Use

- 锁定定义核心：剥离可变特征，找出缺了它该对象就不再是其自身的那个属性。 - 检验替换设想：设想某特征改变后对象是否仍是同一个，避免把偶性误当本质。

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