more on this theme
|
more from this text
Single Idea 20791
[filed under theme 4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
]
Full Idea
Chrysippus has five indemonstrables that do not need demonstration:1) If 1st the 2nd, but 1st, so 2nd; 2) If 1st the 2nd, but not 2nd, so not 1st; 3) Not 1st and 2nd, the 1st, so not 2nd; 4) 1st or 2nd, the 1st, so not 2nd; 5) 1st or 2nd, not 2nd, so 1st.
Gist of Idea
Chrysippus has five obvious 'indemonstrables' of reasoning
Source
report of Chrysippus (fragments/reports [c.240 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.80-81
Book Ref
'The Stoics Reader', ed/tr. Inwood,B/Gerson,L.P. [Hackett 2008], p.22
A Reaction
[from his lost text 'Dialectics'; squashed to fit into one quote] 1) is Modus Ponens, 2) is Modus Tollens. 4) and 5) are Disjunctive Syllogisms. 3) seems a bit complex to be an indemonstrable.
Related Ideas
Idea 8078
Modus ponens is one of five inference rules identified by the Stoics [Chrysippus, by Devlin]
Idea 1875
Dogs show reason in decisions made by elimination [Chrysippus, by Sext.Empiricus]
The
60 ideas
from Chrysippus
9199
|
Wisdom for one instant is as good as wisdom for eternity
[Chrysippus]
|
20853
|
Wise men should try to participate in politics, since they are a good influence
[Chrysippus, by Diog. Laertius]
|
20772
|
Three branches of philosophy: first logic, second ethics, third physics (which ends with theology)
[Chrysippus]
|
5969
|
Chrysippus said the uncaused is non-existent
[Chrysippus, by Plutarch]
|
21388
|
The causes of future true events must exist now, so they will happen because of destiny
[Chrysippus, by Cicero]
|
20780
|
Graspable presentations are criteria of facts, and are molded according to their objects
[Chrysippus, by Diog. Laertius]
|
20793
|
How could you ever know that the presentation is similar to the object?
[Sext.Empiricus on Chrysippus]
|
8077
|
Stoic propositional logic is like chemistry - how atoms make molecules, not the innards of atoms
[Chrysippus, by Devlin]
|
20791
|
Chrysippus has five obvious 'indemonstrables' of reasoning
[Chrysippus, by Diog. Laertius]
|
6023
|
Every proposition is either true or false
[Chrysippus, by Cicero]
|
8078
|
Modus ponens is one of five inference rules identified by the Stoics
[Chrysippus, by Devlin]
|
5992
|
Chrysippus says action is the criterion for existence, which must be physical
[Chrysippus, by Tieleman]
|
21673
|
There are simple and complex facts; the latter depend on further facts
[Chrysippus, by Cicero]
|
16652
|
Stoics categories are Substrate, Quality, Disposition, and Relation
[Chrysippus, by Pasnau]
|
20837
|
Fate is an eternal and fixed chain of causal events
[Chrysippus]
|
16058
|
Dion and Theon coexist, but Theon lacks a foot. If Dion loses a foot, he ousts Theon?
[Chrysippus, by Philo of Alexandria]
|
16059
|
Change of matter doesn't destroy identity - in Dion and Theon change is a condition of identity
[Chrysippus, by Long/Sedley]
|
1875
|
Dogs show reason in decisions made by elimination
[Chrysippus, by Sext.Empiricus]
|
3048
|
Stoics say that God the creator is the perfection of all animals
[Chrysippus, by Diog. Laertius]
|
20834
|
Chrysippus allows evil to say it is fated, or even that it is rational and natural
[Plutarch on Chrysippus]
|
20833
|
A swerve in the atoms would be unnatural, like scales settling differently for no reason
[Chrysippus, by Plutarch]
|
20808
|
Everything is fated, either by continuous causes or by a supreme rational principle
[Chrysippus, by Diog. Laertius]
|
20835
|
Chrysippus is wrong to believe in non-occurring future possibilities if he is a fatalist
[Plutarch on Chrysippus]
|
20836
|
The Lazy Argument responds to fate with 'why bother?', but the bothering is also fated
[Chrysippus, by Cicero]
|
21679
|
When we say events are fated by antecedent causes, do we mean principal or auxiliary causes?
[Chrysippus]
|
20787
|
A proposition is what can be asserted or denied on its own
[Chrysippus]
|
20850
|
Passions are judgements; greed thinks money is honorable, and likewise drinking and lust
[Chrysippus, by Diog. Laertius]
|
20869
|
The highest degree of morality performs all that is appropriate, omitting nothing
[Chrysippus]
|
3044
|
Stoics say that beauty and goodness are equivalent and linked
[Chrysippus, by Diog. Laertius]
|
20838
|
Fate initiates general causes, but individual wills and characters dictate what we do
[Chrysippus]
|
20813
|
Human purpose is to contemplate and imitate the cosmos
[Chrysippus]
|
20774
|
Only nature is available to guide action and virtue
[Chrysippus]
|
3045
|
Stoics say justice is a part of nature, not just an invented principle
[Chrysippus, by Diog. Laertius]
|
20864
|
Live in agreement, according to experience of natural events
[Chrysippus]
|
20855
|
Chrysippus says virtue can be lost (though Cleanthes says it is too secure for that)
[Chrysippus, by Diog. Laertius]
|
5970
|
Chrysippus says nothing is blameworthy, as everything conforms with the best nature
[Chrysippus, by Plutarch]
|
20842
|
Rational animals begin uncorrupted, but externals and companions are bad influences
[Chrysippus, by Diog. Laertius]
|
20856
|
Justice, the law, and right reason are natural and not conventional
[Chrysippus, by Diog. Laertius]
|
1779
|
We don't have obligations to animals as they aren't like us
[Chrysippus, by Diog. Laertius]
|
20857
|
Justice is irrelevant to animals, because they are too unlike us
[Chrysippus, by Diog. Laertius]
|
20812
|
Covers are for shields, and sheaths for swords; likewise, all in the cosmos is for some other thing
[Chrysippus]
|
21403
|
The later Stoics identified the logos with an air-fire compound, called 'pneuma'
[Chrysippus, by Long]
|
20828
|
Fire is a separate element, not formed with others (as was previously believed)
[Chrysippus, by Stobaeus]
|
1777
|
Pleasure is not the good, because there are disgraceful pleasures
[Chrysippus, by Diog. Laertius]
|
20845
|
There are shameful pleasures, and nothing shameful is good, so pleasure is not a good
[Chrysippus, by Diog. Laertius]
|
5967
|
People need nothing except corn and water
[Chrysippus, by Plutarch]
|
1782
|
Stoics teach that God is a unity, variously known as Mind, or Fate, or Jupiter
[Chrysippus, by Diog. Laertius]
|
20819
|
The past and the future subsist, but only the present exists
[Chrysippus, by Plutarch]
|
20818
|
The present does not exist, so our immediate experience is actually part past and part future
[Chrysippus, by Plutarch]
|
20821
|
Time is continous and infinitely divisible, so there cannot be a wholly present time
[Chrysippus, by Stobaeus]
|
20773
|
The origin of justice can only be in Zeus, and in nature
[Chrysippus]
|
3042
|
Stoics teach that law is identical with right reason, which is the will of Zeus
[Chrysippus, by Diog. Laertius]
|
20830
|
Death can't separate soul from body, because incorporeal soul can't unite with body
[Chrysippus]
|
21404
|
There is a rationale in terrible disasters; they are useful to the whole, and make good possible
[Chrysippus]
|
5966
|
All virtue is good, but not always praised (as in not lusting after someone ugly)
[Chrysippus]
|
5973
|
Justice can be preserved if pleasure is a good, but not if it is the goal
[Chrysippus, by Plutarch]
|
5965
|
The source of all justice is Zeus and the universal nature
[Chrysippus]
|
5975
|
Stoics say earth, air, fire and water are the primary elements
[Chrysippus, by Plutarch]
|
5971
|
Destiny is only a predisposing cause, not a sufficient cause
[Chrysippus, by Plutarch]
|
5972
|
Living happily is nothing but living virtuously
[Chrysippus, by Plutarch]
|