26 ideas
| 18739 | Three stages of philosophical logic: syntactic (1905-55), possible worlds (1963-85), widening (1990-) [Horsten/Pettigrew] |
| Full Idea: Three periods can be distinguished in philosophical logic: the syntactic stage, from Russell's definite descriptions to the 1950s, the dominance of possible world semantics from the 50s to 80s, and a current widening of the subject. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 1) | |
| A reaction: [compressed] I've read elsewhere that the arrival of Tarski's account of truth in 1933, taking things beyond the syntactic, was also a landmark. |
| 18741 | Logical formalization makes concepts precise, and also shows their interrelation [Horsten/Pettigrew] |
| Full Idea: Logical formalization forces the investigator to make the central philosophical concepts precise. It can also show how some philosophical concepts and objects can be defined in terms of others. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: This is the main rationale of the highly formal and mathematical approach to such things. The downside is when you impose 'precision' on language that was never intended to be precise. |
| 18744 | Models are sets with functions and relations, and truth built up from the components [Horsten/Pettigrew] |
| Full Idea: A (logical) model is a set with functions and relations defined on it that specify the denotation of the non-logical vocabulary. A series of recursive clauses explicate how truth values of complex sentences are compositionally determined from the parts. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: See the ideas on 'Functions in logic' and 'Relations in logic' (in the alphabetical list) to expand this important idea. |
| 18740 | If 'exist' doesn't express a property, we can hardly ask for its essence [Horsten/Pettigrew] |
| Full Idea: If there is indeed no property of existence that is expressed by the word 'exist', then it makes no sense to ask for its essence. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 2) | |
| A reaction: As far as I can tell, this was exactly Aristotle's conclusion, so he skirted round the question of 'being qua being', and focused on the nature of objects instead. Grand continental talk of 'Being' doesn't sound very interesting. |
| 13120 | Chisholm divides things into contingent and necessary, and then individuals, states and non-states [Chisholm, by Westerhoff] |
| Full Idea: Chisholm's Ontological Categories: ENTIA - {Contingent - [Individual - (Boundaries)(Substances)] [States - (Events)]} {Necessary - [States] [Non-States - (Attributes)(Substance)]} | |
| From: report of Roderick Chisholm (A Realistic Theory of Categories [1996], p.3) by Jan Westerhoff - Ontological Categories §01 | |
| A reaction: [I am attempting a textual representation of a tree diagram! The bracket-styles indicate the levels.] |
| 16665 | There are entities, and then positive 'modes', modifying aspects outside the thing's essence [Suárez] |
| Full Idea: Beyond the entities there are certain real 'modes', which are positive, and in their own right act on those entities, giving them something that is outside their whole essence as individuals existing in reality. | |
| From: Francisco Suárez (Disputationes metaphysicae [1597], 7.1.17), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 13.3 | |
| A reaction: Suárez is apparently the first person to formulate a proper account of properties as 'modes' of a thing, rather than as accidents which are separate, or are wholly integrated into a thing. A typical compromise proposal in philosophy. Can modes act? |
| 16666 | A mode determines the state and character of a quantity, without adding to it [Suárez] |
| Full Idea: The inherence of quantity is called its mode, because it affects that quantity, which serves to ultimately determine the state and character of its existence, but does not add to it any new proper entity, but only modifies the preexisting entity. | |
| From: Francisco Suárez (Disputationes metaphysicae [1597], 7.1.17), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 13.3 | |
| A reaction: He seems to present mode as a very active thing, like someone who gives it a coat of paint, or hammers it into a new shape. I don't see how a 'mode' can have any ontological status at all. To exist, there has to be some way to exist. |
| 16667 | Substances are incomplete unless they have modes [Suárez, by Pasnau] |
| Full Idea: In the view of Suárez, substances are radically incomplete entities that cannot exist at all until determined in various ways by things of another kind, modes. …Modes are regarded as completers for their subjects. | |
| From: report of Francisco Suárez (Disputationes metaphysicae [1597]) by Robert Pasnau - Metaphysical Themes 1274-1671 13.3 | |
| A reaction: This is correct. In order to be a piece of clay it needs a shape, a mass, a colour etc. Treating clay as an object independently from its shape is a misunderstanding. |
| 17007 | Forms must rule over faculties and accidents, and are the source of action and unity [Suárez] |
| Full Idea: A form is required that, as it were, rules over all those faculties and accidents, and is the source of all actions and natural motions of such a being, and in which the whole variety of accidents and powers has its root and unity. | |
| From: Francisco Suárez (Disputationes metaphysicae [1597], 15.1.7), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 24.4 | |
| A reaction: Pasnau emphasises that this is scholastics giving a very physical and causal emphasis to forms, which made them vulnerable to doubts among the new experiment physicists. Pasnau says forms are 'metaphysical', following Leibniz. |
| 16780 | Partial forms of leaf and fruit are united in the whole form of the tree [Suárez] |
| Full Idea: In a tree the part of the form that is in the leaf is not the same character as the part that is in the fruit., but yet they are partial forms, and apt to be united ….to compose one complete form of the whole. | |
| From: Francisco Suárez (Disputationes metaphysicae [1597], 15.10.30), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 26.6 | |
| A reaction: This is a common scholastic view, the main opponent of which was Aquinas, who says each thing only has one form. Do leaves have different DNA from the bark or the fruit? Presumably not (since I only have one DNA), which supports Aquinas. |
| 16758 | The best support for substantial forms is the co-ordinated unity of a natural being [Suárez] |
| Full Idea: The most powerful arguments establishing substantial forms are based on the necessity, for the perfect constitution of a natural being, that all the faculties and operations of that being are rooted in one essential principle. | |
| From: Francisco Suárez (Disputationes metaphysicae [1597], 15.10.64), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 24.4 | |
| A reaction: Note Idea 15756, that this stability not only applies to biological entities (the usual Aristotelian examples), but also to non-living natural kinds. We might say that the drive for survival is someone united around a single entity. |
| 16743 | We can get at the essential nature of 'quantity' by knowing bulk and extension [Suárez] |
| Full Idea: We can say that the form that gives corporeal bulk [molem] or extension to things is the essential nature of quantity. To have bulk is to expel a similar bulk from the same space. | |
| From: Francisco Suárez (Disputationes metaphysicae [1597], 40.4.16), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 539 | |
| A reaction: This is one step away from asking why, once we knew the bulk and extension of the thing, we would still have any interest in trying to grasp something called its 'quantity'. |
| 16742 | We only know essences through non-essential features, esp. those closest to the essence [Suárez] |
| Full Idea: We can almost never set out the essences of things, as they are in things. Instead, we work through their connection to some non-essential feature, and we seem to succeed well enough when we spell it out through the feature closest to the essence. | |
| From: Francisco Suárez (Disputationes metaphysicae [1597], 40.4.16), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 23.5 | |
| A reaction: It is a common view that with geometrical figures we can actually experience the essence itself. So has science broken through, and discerned actual essences of things? |
| 22143 | Identity does not exclude possible or imagined difference [Suárez, by Boulter] |
| Full Idea: To be really the same excludes being really other, but does not exclude being other modally or mentally. | |
| From: report of Francisco Suárez (Disputationes metaphysicae [1597], 7.65) by Stephen Boulter - Why Medieval Philosophy Matters 4 | |
| A reaction: So the statue and the clay are identical, but they could become separate, or be imagined as separate. |
| 22144 | Real Essential distinction: A and B are of different natural kinds [Suárez, by Boulter] |
| Full Idea: The Real Essential distinction says if A and B are not of the same natural kind, then they are essentially distinct. This is the highest degree of distinction. | |
| From: report of Francisco Suárez (Disputationes metaphysicae [1597], Bk VII) by Stephen Boulter - Why Medieval Philosophy Matters 4 | |
| A reaction: Boulter says Peter is essentially distinct from a cabbage, because neither has the nature of the other. |
| 22146 | Minor Real distinction: B needs A, but A doesn't need B [Suárez, by Boulter] |
| Full Idea: The Minor Real distinction is if A can exist without B, but B ceases to exist without A. | |
| From: report of Francisco Suárez (Disputationes metaphysicae [1597], Bk VII) by Stephen Boulter - Why Medieval Philosophy Matters 4 | |
| A reaction: This is one-way independence. Boulter's example is Peter and Peter's actual weight. |
| 22145 | Major Real distinction: A and B have independent existences [Suárez, by Boulter] |
| Full Idea: The Major Real distinction is if A can exist in the real order without B, and B can exist in the real order without A. | |
| From: report of Francisco Suárez (Disputationes metaphysicae [1597], Bk VII) by Stephen Boulter - Why Medieval Philosophy Matters 4 | |
| A reaction: Boulter's example is the distinction between Peter and Paul, where their identity of kind is irrelevant. This is two-way independence. |
| 22147 | Conceptual/Mental distinction: one thing can be conceived of in two different ways [Suárez, by Boulter] |
| Full Idea: The Conceptual or Mental distinction is when A and B are actually identical but we have two different ways of conceiving them. | |
| From: report of Francisco Suárez (Disputationes metaphysicae [1597], Bk VII) by Stephen Boulter - Why Medieval Philosophy Matters 4 | |
| A reaction: This is the Morning and Evening Star. I bet Frege never read Suarez. This seems to be Spinoza's concept of mind/body. |
| 22148 | Modal distinction: A isn't B or its property, but still needs B [Suárez, by Boulter] |
| Full Idea: The Modal distinction is when A is not B or a property of B, but still could not possibly exist without B. | |
| From: report of Francisco Suárez (Disputationes metaphysicae [1597], Bk VII) by Stephen Boulter - Why Medieval Philosophy Matters 4 | |
| A reaction: Duns Scotus proposed in, Ockham rejected it, but Suarez supports it. Suarez proposes that light's dependence on the Sun is distinct from the light itself, in this 'modal' way. |
| 22149 | Scholastics assess possibility by what has actually happened in reality [Suárez, by Boulter] |
| Full Idea: The scholastic view is that Actuality is our only guide to possibility in the real order. One knows that it is possible to separate A and B if one knows that A and B have actually been separated or are separate. | |
| From: report of Francisco Suárez (Disputationes metaphysicae [1597], Bk VII) by Stephen Boulter - Why Medieval Philosophy Matters 4 | |
| A reaction: It may be possible to separate A and B even though it has never happened, but it is hard to see how we could know that. (But if I put my pen down where it has never been before, I know I can pick it up again, even though this has not previously happened). |
| 18745 | A Tarskian model can be seen as a possible state of affairs [Horsten/Pettigrew] |
| Full Idea: A Tarskian model can in a sense be seen as a model of a possible state of affairs. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: I include this remark to show how possible worlds semantics built on the arrival of model theory. |
| 18747 | The 'spheres model' was added to possible worlds, to cope with counterfactuals [Horsten/Pettigrew] |
| Full Idea: The notion of a possible worlds model was extended (resulting in the concept of a 'spheres model') in order to obtain a satisfactory logical treatment of counterfactual conditional sentences. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Thus we add 'centred' worlds, and an 'actual' world, to the loose original model. It is important to remember when we discuss 'close' worlds that we are then committed to these presuppositions. |
| 18748 | Epistemic logic introduced impossible worlds [Horsten/Pettigrew] |
| Full Idea: The idea of 'impossible worlds' was introduced into epistemic logic. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 4) | |
| A reaction: Nathan Salmon seems interested in their role in metaphysics (presumably in relation to Meinongian impossible objects, like circular squares, which must necessarily be circular). |
| 18746 | Possible worlds models contain sets of possible worlds; this is a large metaphysical commitment [Horsten/Pettigrew] |
| Full Idea: Each possible worlds model contains a set of possible worlds. For this reason, possible worlds semantics is often charged with smuggling in heavy metaphysical commitments. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 3) | |
| A reaction: To a beginner it looks very odd that you should try to explain possibility by constructing a model of it in terms of 'possible' worlds. |
| 18750 | Using possible worlds for knowledge and morality may be a step too far [Horsten/Pettigrew] |
| Full Idea: When the possible worlds semantics were further extended to model notions of knowledge and of moral obligation, the application was beginning to look distinctly forced and artificial. | |
| From: Horsten,L/Pettigrew,R (Mathematical Methods in Philosophy [2014], 5) | |
| A reaction: They accept lots of successes in modelling necessity and time. |
| 16682 | Other things could occupy the same location as an angel [Suárez] |
| Full Idea: An angelic substance could be penetrated by other bodies in the same location. | |
| From: Francisco Suárez (Disputationes metaphysicae [1597], 40.2.21), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 15.3 | |
| A reaction: So am I co-located with an angel right now? |