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Single Idea 15879
[filed under theme 4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
]
Full Idea
Square of Opposition: 'all A are B' and 'no A are B' are contraries; 'some A are B' and 'some A are not B' are sub-contraries; the pairs 'all A are B'/'some A are B' and 'no A are B'/'some A are B' are contradictories.
Gist of Idea
The Square of Opposition has two contradictory pairs, one contrary pair, and one sub-contrary pair
Source
Rom Harré (Laws of Nature [1993], 3)
Book Ref
Harré,Rom: 'Laws of Nature' [Duckworth 1993], p.62
A Reaction
[the reader may construct his own diagram from this description!] The contraries are at the extremes of contradiction, but the sub-contraries are actual compatible. You could add possible worlds to this picture.
Related Idea
Idea 9405
Square of Opposition: not both true, or not both false; one-way implication; opposite truth-values [Aristotle]
The
27 ideas
from 'Laws of Nature'
15869
|
Reports of experiments eliminate the experimenter, and present results as the behaviour of nature
[Harré]
|
15864
|
Classification is just as important as laws in natural science
[Harré]
|
15865
|
Newton's First Law cannot be demonstrated experimentally, as that needs absence of external forces
[Harré]
|
15862
|
Laws can come from data, from theory, from imagination and concepts, or from procedures
[Harré]
|
15860
|
We take it that only necessary happenings could be laws
[Harré]
|
15867
|
Laws describe abstract idealisations, not the actual mess of nature
[Harré]
|
15868
|
Idealisation idealises all of a thing's properties, but abstraction leaves some of them out
[Harré]
|
15875
|
In counterfactuals we keep substances constant, and imagine new situations for them
[Harré]
|
15876
|
Maybe laws of nature are just relations between properties?
[Harré]
|
15872
|
Must laws of nature be universal, or could they be local?
[Harré]
|
15870
|
Are laws of nature about events, or types and universals, or dispositions, or all three?
[Harré]
|
15871
|
Are laws about what has or might happen, or do they also cover all the possibilities?
[Harré]
|
15874
|
Scientific properties are not observed qualities, but the dispositions which create them
[Harré]
|
15879
|
The Square of Opposition has two contradictory pairs, one contrary pair, and one sub-contrary pair
[Harré]
|
15880
|
In physical sciences particular observations are ordered, but in biology only the classes are ordered
[Harré]
|
15881
|
We can save laws from counter-instances by treating the latter as analytic definitions
[Harré]
|
15882
|
Since there are three different dimensions for generalising laws, no one system of logic can cover them
[Harré]
|
15878
|
Some quantifiers, such as 'any', rule out any notion of order within their range
[Harré]
|
15885
|
The necessity of Newton's First Law derives from the nature of material things, not from a mechanism
[Harré]
|
15884
|
Laws of nature remain the same through any conditions, if the underlying mechanisms are unchanged
[Harré]
|
15890
|
Non-black non-ravens just aren't part of the presuppositions of 'all ravens are black'
[Harré]
|
15891
|
Traditional quantifiers combine ordinary language generality and ontology assumptions
[Harré]
|
15888
|
The grue problem shows that natural kinds are central to science
[Harré]
|
15887
|
'Grue' introduces a new causal hypothesis - that emeralds can change colour
[Harré]
|
15889
|
It is because ravens are birds that their species and their colour might be connected
[Harré]
|
15886
|
Science rests on the principle that nature is a hierarchy of natural kinds
[Harré]
|
15892
|
Laws of nature state necessary connections of things, events and properties, based on models of mechanisms
[Harré]
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