Inductive VS Deductive.
September 27, 2019 at 11:27 pm #28631
Hello everyone. I am happy I found your forum!
I am taking a philosophy course and I am just a bit confused about the two arguments that I need to show which is deductive and the other inductive.
Argument A: 1. When we observe our world, we see that there is widespread disagreement among cultures about what is moral.2. The best explanation of this widespread disagreement is that what makes something moral just is that it is accepted as moral by a given culture.3. Therefore, what makes something moral just is that it is accepted as moral by a given culture.
Argument B: 1. If we observe widespread disagreement about morality among cultures then what makes something moral just is that it is accepted as moral by a given culture.2. We observe widespread disagreement about morality among cultures.3. Therefore, what makes something moral just is that it is accepted as moral by a given culture.
I believe argument B is the one that is deductive am I right or wrong? It’s just all new to me and get a bit confused
I also need to find out the FORM of each.
I really can use some help from anyone. Thank you so much.September 27, 2019 at 11:53 pm #28632
Ehhh. I’d say your professor did not choose his examples well. Those two arguments are barely different. Certainly not distinctive enough to say one is deductive and the other inductive. Though yeah, I’d say B is a little more deductive than A but ONLY because of the kind of language used…not the arguments. The best trick I learnt to easily distinguish them was deductive simmers down while inductive steams away (creating a broader conceptual conclusion). It’s not precise but it helps in principle. B slightly simmers down an argument (though its based itself on an inductive premise which is explained within the argument for some reason) while A seems to both simmer and steam away. I don’t think either of these examples are particularly representative of inductive or deductive arguments and I’d even say that both of them are a little ambiguous. Especially A. Could you give us another example from the exercises they gave you?September 28, 2019 at 12:20 am #28633
Thanks Davis for responding. Indeed it confused me but I think it’s on purpose that the professor put these two similar arguments, but written differently.
So we had one argument that said: Everything my mother says is true. My mother says god exists. Therefore, god exists.
That was seen in class as a deductive argument since the premises are true then the conclusion can’t be false.
then we had to show if it was valid and sound.
Now I know these sentences are stupid, but we are not talking about whether or not it is.September 28, 2019 at 2:31 am #28634
Yes indeed, an argument could be sound but still be false.
- All round metal objects are coins
- Washers are round metal objects
- Therefore washers are coins.
The argument is sound because the conclusion logically follows from the premises. However one of the premises is not the case (all round metal objects are coins) and therefore we cannot use this conclusion through the means of those premises or this type of argument. You’d have to prove or falsify this conclusion by other arguments or other means.
And argument can be sound, yet based on a false premise, and yet still be the case. My favorite example is something like this:
- All white animals are mammals
- Polar bears are white
- Therefore polar bears are mammals.
The argument is sound (because the conclusion logically follows from the two premises). And the conclusion is also true (we know that polar bears are mammals because they lactate and have distinctive body parts). However one of the premises is not the case (that all white animals are mammals) as there are white birds, insects and fish as well as albino reptiles etc. And so while the argument is sound, yet one premises is not the case…the conclusion still turns out to be the case which is an important lesson in the study of fallacies. The fallacy fallacy. Just because the argument is fallicious doesn’t mean the conclusion is not the case. I personally think its the most important fallacy, more than straw manning or red herring or a fallacy (or fallicious form of arguing) which is common these days: the gish gallop and closely related sea-lioning. The internet comment sections, facebook commentary and tweets, especially on political topics are utterly overflowing with falicious content. There is just so much bad argument out there it’s a wonder we maintain a stable democracy despite our lack of reasoning skills. Which is why I basically avoid twitter and comment sections cause, you can only bear so much nonsense.
Have fun studying them. Critical thinking rocked my world when I studied it.September 28, 2019 at 3:47 am #28636
In real life, we probably use abductive reasoning more than either deduction or induction. You come home to find that a small glass you left on the kitchen counter is on the floor broken. You have a cat. You know your cat (like all cats) likes to knock things off tables and counters onto the floor. Looks like it was something the cat did. Like inductive reasoning, the conclusion isn’t certain, but often it’s simply a “best guess” kind of thing and really the only logic available and practical to apply.
Mention abductive argumentation and maybe you’ll get a brownie point or two.
September 28, 2019 at 2:37 pm #28642
- This reply was modified 8 months ago by Unseen.
So I understand with the example you gave me. However, how do I do to show VALIDITY which I seem to confuse with SOUNDNESS? It’s funny because I understand it but when I need to write write it, it becomes complicated.September 28, 2019 at 4:05 pm #28644
So I understand with the example you gave me. However, how do I do to show VALIDITY which I seem to confuse with SOUNDNESS? It’s funny because I understand it but when I need to write write it, it becomes complicated.
“Validity” applies to deductive arguments only and refers to the form of the argument, not the content. “A deductive argument is said to be valid if and only if it takes a form that makes it impossible for the premises to be true and the conclusion nevertheless to be false. Otherwise, a deductive argument is said to be invalid.” (source)
Go to that source for a clear and lengthy discussion of the matter peppered with lots of examples. Read it through and you’ll understand.
A sound argument is a valid argument whose premises are all true.
Look these arguments over and decide which ones are valid and which are invalid, then which are sound and which are unsound, bearing in mind that I’m being tricky. You will likely need to do some Googling to determine which premises are true and which are not:
popcorn is a snack
snacks are healthy
thus, popcorn is healthy
sodium is a metal
metals are malleable
thus, sodium is malleable
Trump is our President
Presidents are truthful
thus, Trump is truthful
mammals are four-legged
dogs are mammals
thus, dogs are four-legged
fish have fins
whales have fins
thus, whales are fish
philosophers are logicians
logicians are boring
thus, philosophers are boring (LOL)
gemstones are minerals
minerals are nonorganic
thus gemstones are nonorganic
mites are insects
insects are arthropods
thus, mites are arthropods
Also, not how seldom you reason this way in everyday life. Abduction. Abduction. Applying experience to reality.
September 28, 2019 at 4:26 pm #28646
- This reply was modified 8 months ago by Unseen.
Yes indeed…I totally screwed up on my conflation of sound Vs. valid argument which likely confused you so that’s my fault. In the texts I wrote you should substitute sound with valid.
Valid = logically follows
Sound = yes yes yesSeptember 28, 2019 at 11:33 pm #28648
Thank you so much I understand now. It is still hard to put on paper because i have to explain which argument is inductive/deductive – that we figured out.
I have to determine the form and explain why the deductive argument is valid or not
And finally, determine if each is rationally persuasive or not ans why.
It’s funny because in Philo it’s like it’s all in the head because I understand (most) of the subject, but I’m blocking once I need to write about it.September 29, 2019 at 9:02 am #28649
Reg the Fronkey FarmerModerator
I understand (most) of the subject, but I’m blocking once I need to write about it.
When we don’t yet fully understood a topic we can use the Feynman Technique which is a great way to master any topic so you will not have to relearn it in the future, just quickly revise it a day or two before an exam.
Here is a synopsis of each of the 3 forms of reasoning discussed earlier. As well as the term “abductive” mentioned by Unseen, I would recommend introducing some (or all) of these “causal reasoning fallacies” into your paper. A good one to be able to spot is the “Non-Sequitur” (which I find I use a lot when confronting the poorly constructed arguments of theists).
PS I have a video with Feynman in Sunday School this week.
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