Two related claims have lately garnered currency: dispositional essentialism—the view that some or all properties, or some or all fundamental properties, are essentially dispositional; and the claim that laws of nature (or again, many or the fundamental ones) are metaphysically necessary. I have argued elsewhere (On the metaphysical contingency of laws of nature, Oxford University Press, Oxford, 2002) that the laws of nature do not have a mind-independent metaphysical necessity, but recent developments on dispositions have given these ideas a new vibrancy and made them the topic of more focused discussion. So I would like to revisit this, arguing that the new work, as interesting and important as it is to our understanding of fundamental properties, powers and dispositions, should not change our minds about metaphysical necessity. One should still think necessity is conceptually or conventionally grounded. I do not argue that laws of nature are not necessary, nor that properties do not have dispositional essences, but only that if these are the case, then, like other de re or empirical necessities, they have no metaphysical weight and are based in our rules or decisions about how to talk about the world. We may have excellent reasons to talk and think in this way—but these reasons do not include, require or provide evidence of mind-independent metaphysical necessity or essences.

两个相关的主张最近流行起来：倾向性本质主义——认为部分或所有属性，或部分或所有基本属性本质上是倾向性的观点；并声称自然法则（或许多或基本法则）在形而上学上是必要的。我在其他地方论证过（关于自然法则的形而上学偶然性，牛津大学出版社，牛津，2002 年），自然法则没有独立于心灵的形而上学必然性，但最近关于倾向的发展赋予了这些想法新的活力和使他们成为更集中讨论的话题。因此，我想重新审视这一点，认为这项新工作尽管对我们理解基本属性、权力和倾向来说既有趣又重要，但不应改变我们对形而上学必然性的看法。人们仍然应该认为必然性是基于概念或约定俗成的。我不争辩说自然法则不是必然的，也不争辩说属性没有倾向性本质，而只是说如果是这样的话，那么它们就像其他从属物或经验的必然性一样，没有形而上学的分量，而是基于我们的关于如何谈论世界的规则或决定。我们可能有很好的理由以这种方式谈论和思考——但这些理由不包括、要求或提供独立于心灵的形而上学必然性或本质的证据。它们没有形而上学的分量，而是基于我们关于如何谈论世界的规则或决定。我们可能有很好的理由以这种方式谈论和思考——但这些理由不包括、要求或提供独立于心灵的形而上学必然性或本质的证据。它们没有形而上学的分量，而是基于我们关于如何谈论世界的规则或决定。我们可能有很好的理由以这种方式谈论和思考——但这些理由不包括、要求或提供独立于心灵的形而上学必然性或本质的证据。