| 22505 | The two right angles of a triangle necessitate that a quadrilateral has four [Aristotle] |
| Full Idea: If it is necessary that, if a triangle contains two right angles, that a quadrilateral has four, it is clear that the cause of this is that a triangle has two. | |
| From: Aristotle (Eudemian Ethics [c.333 BCE], 1222b31) | |
| A reaction: We would not normally use the word 'cause' for this, but 'necessitates' seems to fit, and I like the word 'determines' (because it can be both physical and abstract). An example of what I think of as an Aristotelian necessity maker. |
| 12612 | Some things have external causes of their necessity; others (the simple) generate necessities [Aristotle] |
| Full Idea: For some things, the cause of their necessity is something other than themselves, whereas for others there is no such external cause, but rather they are themselves the necessary cause of other things being the case. The simple is fundamentally necessary. | |
| From: Aristotle (Metaphysics [c.324 BCE], 1015b14) | |
| A reaction: What is 'simple' is what terminates an explanation, and that is what-it-is-to-be each thing (its essence). The Greek view of necessity always seems to be a power to which we submit, rather than a passive state like true-in-all-worlds. |
| 15108 | Aristotle's says necessary truths are distinct and derive from essential truths [Aristotle, by Koslicki] |
| Full Idea: Aristotle conceives of the necessary truths as being distinct and derivative from the essential truths. | |
| From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Kathrin Koslicki - Essence, Necessity and Explanation 13.1 | |
| A reaction: This is precisely the view promoted by Kit Fine in 1994. It seems to fragment necessity, because there are many different necessities based on many different foundations. |
| 17182 | Necessity is in reference to essence or to cause [Spinoza] |
| Full Idea: A thing is called necessary either in reference to its essence or its cause. | |
| From: Baruch de Spinoza (The Ethics [1675], I Pr 33) | |
| A reaction: I like any proposal that necessity should be 'in reference to' something, rather than being free-standing. I like to add necessary 'for' something, which is often conceptual necessity. Roots are necessary for trees. |
| 5447 | Metaphysical necessities are true in virtue of the essences of things [Ellis] |
| Full Idea: Metaphysical necessities are propositions that are true in virtue of the essences of things. | |
| From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.1) | |
| A reaction: I am cautious about this. It sounds like huge Leibnizian metaphysical claims riding in on the back of a rather sensible new view of the laws of science. How can we justify equating natural necessity with metaphysical necessity? |
| 13570 | Individual essences necessitate that individual; natural kind essences necessitate kind membership [Ellis] |
| Full Idea: There are necessities grounded in the individual real essences of things, and necessities grounded in the natural kind essences of things. In the first case, without the property it isn't that individual, and in the second it isn't a member of that kind. | |
| From: Brian Ellis (Scientific Essentialism [2001], Intro) | |
| A reaction: This is the distinction we must hang onto to avoid a huge amount of confusion in this territory. I just say that ceasing to be that individual will presumably entail ceasing to be that kind, but not necessarily vice versa, so individual essences rule. |
| 11162 | Socrates is necessarily distinct from the Eiffel Tower, but that is not part of his essence [Fine,K] |
| Full Idea: It is necessary that Socrates and the Eiffel Tower be distinct. But it is not essential to Socrates that he be distinct from the Tower, for there is nothing in his nature which connects him in any special way to it. | |
| From: Kit Fine (Essence and Modality [1994], p. 5) | |
| A reaction: I find this simple argument very persuasive in separating out necessary facts about an object from the essence of that object. |
| 11168 | Metaphysical necessities are true in virtue of the nature of all objects [Fine,K] |
| Full Idea: The metaphysically necessary truths can be identified with the propositions which are true in virtue of the nature of all objects whatever. | |
| From: Kit Fine (Essence and Modality [1994], p. 9) | |
| A reaction: This is part of Fine's proposal that necessities are derived from the essences or natures of things, which view I find very congenial. |
| 15070 | It is the nature of Socrates to be a man, so necessarily he is a man [Fine,K] |
| Full Idea: It is of the nature of Socrates to be a man; and from this it appears to follow that necessarily he is a man. | |
| From: Kit Fine (Necessity and Non-Existence [2005], 04) | |
| A reaction: I'm always puzzled by this line of thought, because it is only the intrinsic nature of beings like Socrates which decides in the first place what a 'man' is. How can something help to create a category, and then necessarily belong to that category? |
| 5449 | Essentialism is often identified with belief in 'de re' necessary truths [Mautner] |
| Full Idea: Many writers identify essentialism with the belief in 'de re' necessary truths | |
| From: Thomas Mautner (Penguin Dictionary of Philosophy [1996], p.179) | |
| A reaction: I like essentialism, but I cautious about this. If I accept that I have an essential personal identity as I write this, but that it could change over time, the same principle might apply to other natural essences. |
| 18502 | If basic physics has natures, then why not reality itself? That would then found the deepest necessities [Heil] |
| Full Idea: If electrons and gravitational fields have definite natures, why not reality itself? And if reality has a nature, if this makes sense, then reality grounds the deepest necessities of all. | |
| From: John Heil (The Universe as We Find It [2012], 08.09) | |
| A reaction: Nice speculation! Scientists and verificationists seem to cry 'foul!' when philosophers offer such wild speculations, but I say that's exactly what we pay them do. I'm not sure whether I understand reality having its own nature, though! |
| 16543 | If an essence implies p, then p is an essential truth, and hence metaphysically necessary [Lowe] |
| Full Idea: If we can truly affirm that it is part of the essence of some entity that p is the case, then p is an essential truth and so a metaphysically necessary truth. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: This feels too quick. He is trying to expound the idea (which I like) that necessity derives from essences, and not vice versa. Is it a metaphysical necessity that there are no moths in my wardrobe, because mothballs have driven them away? Maybe. |
| 16544 | Metaphysical necessity is either an essential truth, or rests on essential truths [Lowe] |
| Full Idea: A metaphysically necessary truth is a truth which is either an essential truth or a truth that obtains in virtue of the essences of two or more distinct things. Hence all metaphysical necessity is grounded in essence. | |
| From: E.J. Lowe (What is the Source of Knowledge of Modal Truths? [2013], 6) | |
| A reaction: Lowe is endeavouring to give an exposition of the approach advocated by Kit Fine. I divide necessities 'because of' things (such as essences) from necessities 'for' things, such as situations or events. |
| 19276 | The big challenge for essentialist views of modality is things having necessary existence [Hale] |
| Full Idea: Whether the essentialist theory can account for all absolute necessities depends in part on whether the theory can explain the necessities of existence (of certain objects, properties and entities). | |
| From: Bob Hale (Necessary Beings [2013], Intro) | |
| A reaction: Hale has a Fregean commitment to all sorts of abstract objects, and then finds difficulty in explaining them from his essentialist viewpoint. His book didn't convince me. I'm more of a nominalist, me, so I sleep better at nights. |
| 19293 | Essentialism doesn't explain necessity reductively; it explains all necessities in terms of a few basic natures [Hale] |
| Full Idea: The point of the essentialist theory is not to provide a reductive explanation of necessities. It is, rather, to locate a base class of necessities - those which directly reflect the natures of things - in terms of which the remainder may be explained. | |
| From: Bob Hale (Necessary Beings [2013], 06.6) | |
| A reaction: My picture is of most of the necessities being directly explained by the natures of things, rather than a small core of natures generating all the derived ones. All the necessities of squares derive from the nature of the square. |
| 19294 | If necessity derives from essences, how do we explain the necessary existence of essences? [Hale] |
| Full Idea: If the essentialist theory of necessity is to be adequate, it must be able to explain how the existence of certain objects - such as the natural numbers - can itself be absolutely necessary. | |
| From: Bob Hale (Necessary Beings [2013], 07.1) | |
| A reaction: Hale and his neo-logicist pals think that numbers are 'objects', and they necessarily exist, so he obviously has a problem. I don't see any alternative for essentialists to treating the existing (and possible) natures as brute facts. |
| 14371 | We can base counterfactuals on powers, not possible worlds, and hence define necessity [Jacobs] |
| Full Idea: Together with a definition of possibility and necessity in terms of counterfactuals, the powers semantics of counterfactuals generates a semantics for modality that appeals to causal powers and not possible worlds. | |
| From: Jonathan D. Jacobs (A Powers Theory of Modality [2010], §1) | |
| A reaction: Wonderful. Just what the doctor ordered. The only caveat is that if we say that reality is built up from fundamental powers, then might those powers change their character without losing their identity (e.g. gravity getting weaker)? |