20 ideas
| 3798 | An overexamined life is as bad as an unexamined one [Dennett] |
| Full Idea: The unexamined life may not be worth living, but the overexamined life is nothing to write home about either. | |
| From: Daniel C. Dennett (Elbow Room: varieties of free will [1984], §4.2) | |
| A reaction: Presumably he means a life which is all theory and no practice. Compare Idea 343. |
| 3801 | Rationality requires the assumption that things are either for better or worse [Dennett] |
| Full Idea: We must assume that something matters - that some things are for better and some things are for worse, for without that our assumed rationality would have nothing on which to get a purchase. | |
| From: Daniel C. Dennett (Elbow Room: varieties of free will [1984], §7.1) | |
| A reaction: It does seem that rationality wouldn't exist as an activity without some value to motivate it. |
| 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. |
| 3802 | Why pronounce impossible what you cannot imagine? [Dennett] |
| Full Idea: You say you cannot imagine that p, and therefore declare that p is impossible. Mightn't that be hubris? | |
| From: Daniel C. Dennett (Elbow Room: varieties of free will [1984], §7.3) |
| 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. |
| 3795 | Causal theories require the "right" sort of link (usually unspecified) [Dennett] |
| Full Idea: In causal theories of knowledge and reference, the causal chain between object and thought must be of the "right" sort - the nature of rightness to be specified later, typically. | |
| From: Daniel C. Dennett (Elbow Room: varieties of free will [1984], §3.3 n14) | |
| A reaction: This is now the standard objection to a purely causal account of reference. Which of the many causal chains causes the meaning? Knowledge of maths is a further problem for it. |
| 3797 | I am the sum total of what I directly control [Dennett] |
| Full Idea: Control is the ultimate criterion of the self: I am the sum total of the parts I control directly. | |
| From: Daniel C. Dennett (Elbow Room: varieties of free will [1984], §4.2) | |
| A reaction: This looks awfully like a flagrant self-contradiction, and I think it is. It seems pretty obvious that there is at least a distinction between the bit or bits that do the controlling, and the bits that get controlled. |
| 3800 | You can be free even though force would have prevented you doing otherwise [Dennett, by PG] |
| Full Idea: If a brain implant would compel you to perform an action which you in fact freely choose, then you are free, but couldn't have done otherwise. | |
| From: report of Daniel C. Dennett (Elbow Room: varieties of free will [1984], §6.1) by PG - Db (ideas) |
| 3803 | Can we conceive of a being with a will freer than our own? [Dennett] |
| Full Idea: Can I even conceive of beings whose wills are freer than our own? | |
| From: Daniel C. Dennett (Elbow Room: varieties of free will [1984], §7.3) |
| 3791 | Awareness of thought is a step beyond awareness of the world [Dennett] |
| Full Idea: The creature who is not only sensitive to patterns in its environment, but also sensitive to patterns in its own reactions to patterns in its environment, has taken a major step. | |
| From: Daniel C. Dennett (Elbow Room: varieties of free will [1984], §2.2) |
| 3794 | Foreknowledge permits control [Dennett] |
| Full Idea: Foreknowledge is what permits control. | |
| From: Daniel C. Dennett (Elbow Room: varieties of free will [1984], §3.2) |
| 3796 | The active self is a fiction created because we are ignorant of our motivations [Dennett] |
| Full Idea: Faced with our inability to 'see' where the centre or source of our free actions is,…we exploit the gaps in our self-knowledge by filling it with a mysterious entity, the unmoved mover, the active self. | |
| From: Daniel C. Dennett (Elbow Room: varieties of free will [1984], §4.1) | |
| A reaction: I am convinced that there is no such things as free will; its origins are to be found in religion, where it is a necessary feature of a very supreme God. I don't believe for a moment that we need to believe in free will. |
| 7331 | A theory of meaning comes down to translating sentences into Fregean symbolic logic [Davidson, by Macey] |
| Full Idea: For a theory of meaning for a fragment of natural language, what Davidson requires, in effect, is that the sentences be translatable into the language of Frege's symbolic logic. | |
| From: report of Donald Davidson (In Defence of Convention T [1973]) by David Macey - Penguin Dictionary of Critical Theory | |
| A reaction: This assumes the adequacy of Fregean logic, which seems unlikely. Is this the culmination of Leibniz's dream of a fully logical language - so that anything that won't fit into our logical form is ruled (logical positivist style) as meaningless? |