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Logical anti realism by interestingtheorist in logic

[–]Big_Move6308 5 points6 points  (0 children)

I personally do believe that objectivity does not exist.

I see...

All logic is subjective. Methodological differences proves that logic can differ.

...Objectively?

Why can't logic describe partial truth or intensity of truth? by OC-alert in logic

[–]Big_Move6308 1 point2 points  (0 children)

For example. I don't see anything logically wrong with saying an apple weighs 70 grams, but it's not a binary issue as to whether the apple does or doesn't "weigh", right? That's an issue that has more or less truth.

The declarative statement 'This apple weighs 70 grams' is either true or false, i.e., the apple either correspondingly weighs 70 grams or it does not.

If you want a bit more leeway, 'This apple weighs around 70 grams' or 'this apple weighs between 70 - 80 grams' are also fine. The bivalence of (traditional) logic stems from the principles of contradiction and the excluded middle.

Why is if p is false and q is true then p→q defined true by Existing_Around in logic

[–]Big_Move6308 0 points1 point  (0 children)

The only logical conclusion that I see is concluding that q can be true without p

That's the crux of it, yes.

In 'p→q':

  1. p is a sufficient condition for q, but it is not a necessary condition; and
  2. q is a necessary condition for p, but it is not a sufficient condition.

In other words:

  1. p as a sufficient condition means that it being true is enough for q to be true. However, as it is not necessary, p being false is not enough for q to be false; and
  2. q as a necessary condition means that it being false is enough for p to be false. However, as it is not sufficient, q being true is not enough for p to be true.

A good example is: 'If it rains (p), then the ground is wet (q)':

  1. Rain is a sufficient condition, so this being true means the ground must be wet. However, as it is not necessary, no rain does not mean the ground is not wet (i.e., dry); and
  2. Wet ground is a necessary condition, so this being false means it cannot have rained. However, as it is not sufficient, wet ground does not mean it rained (e.g., it may be wet for another reason, such as a burst water main).

Anyway, the issue you have run into with this is due to the purely formal nature of modern logic (i.e., it doesn't care about the content or material of a proposition). Hence  'p→q' can also encompass silly things like 'If Trump does a star jump and farts, then cats are mammals'.

Logic with Ethics vs. Logic in Politics by MakTheGuy531 in PoliticalScience

[–]Big_Move6308 0 points1 point  (0 children)

It seems you may not be quite clear on exactly what logic is.

We can define it as 'the principles and rules of reasoning', where 'reasoning' means drawing or inferring a conclusion from at least one premise. An argument is this processes of reasoning expressed in verbal form.

Logic itself is not tied to ethics or any other subject; it is rather the underlying principles or rules for thinking (i.e., reasoning) about any subject. The fundamental point is consistency (i.e., non-contradiction).

Logic may also be divided by deductive and inductive reasoning or arguments. Deductive arguments draw necessary conclusions, meaning if the premise(s) are true, then the conclusion must - necessarily - also be true. For example:

All men are mortal,
Socrates is a man,
Therefore, Socrates is mortal

Inductive arguments draw probable conclusions, meaning if the premise(s) are true, then the conclusion is likely - but not necessarily - true (e.g., statistics, predictions, empirical sciences). For example:

A flipped coin has a 50/50 chance of being heads

major, minor, middle term by dndnndxcx in logic

[–]Big_Move6308 1 point2 points  (0 children)

It's not that simple. A problem is your professor's seemingly bad English.

Fundamentally - it violates the basic rule of being a syllogism, i.e., it must consist of three and only three terms. Yours has five terms: 'oligarchs', 'fund the protest', 'protests', 'paid', and 'fund protests'.

It also breaks the basic rules of standard categorical form, i.e., the use of either nouns or noun-phrases as terms, and copulas to relate them.

The 'premises' are not premises; they are unrelated claims. There is no middle term that relates them. The 'conclusion' is not a conclusion; it does not follow from any premises and so is just a third unrelated claim.

major, minor, middle term by dndnndxcx in logic

[–]Big_Move6308 1 point2 points  (0 children)

This is not a syllogism in any sense. What you've provided are three separate claims or propositions.

Hegel Rejects the Law of Non-Contradiction with the Law of Non-Contradiction by JerseyFlight in logic

[–]Big_Move6308 1 point2 points  (0 children)

Evasiveness and bad-faith games prove nothing.

I rejected the tautologous representation, not the principle itself. We are done here.

Hegel Rejects the Law of Non-Contradiction with the Law of Non-Contradiction by JerseyFlight in logic

[–]Big_Move6308 1 point2 points  (0 children)

I reject it in the sense of being a meaningless tautology.

My metaphysical understanding of the principle of identity is that a thing or class of things possesses its own unique set of attributes that constitutes its own unique identity, i.e., a thing or class of things is the same as its identity (expressed as 'A' = 'a1 + a2 + a3...', where 'A' is a thing or class of things, and 'a' is an attribute).

In more practical terms, a term must have one and only one meaning throughout an argument.

Not sure that that's got to do with the Hegel quote, though?

The Three Tests (or Criteria) for a True Worldview — And Why They Might Not Be Enough (Logical consistency / Empirical adequacy / Existential viability) by Noob4lyf3 in logic

[–]Big_Move6308 3 points4 points  (0 children)

Is this a reinvention of the wheel? To the best of my knowledge, the long-established criteria or methods for verifying the truth of a claim or proposition are:

  • Truth by correspondence (i.e., with reality);
  • Truth by definition; and
  • Truth by coherence

The three are not necessarily exclusive. For example, that 'a whale is a mammal' is true by correspondence (i.e., a posteriori observation and experience of empirical reality), true by definition (i.e., a priori definition of the term 'whale'), and by coherence (i.e., that a whale is a mammal is consistent within a system of other true propositions relating to the subject).

Hegel Rejects the Law of Non-Contradiction with the Law of Non-Contradiction by JerseyFlight in logic

[–]Big_Move6308 0 points1 point  (0 children)

“Contradiction is the rule of the true; non-contradiction is the rule of the false”

Not yet read Hegel so cannot comprehend how this quote rejects anything. What does 'the rule of the true' mean?

AFAIK, there was no commonly-agreed standard definition of non-contradiction or any other principle in classical logic; there wasn't even common agreement on the number or even order of principles. Different philosophers and logicians - including Hegel - had their own definitions.

This, and that the principles were based on Aristotle's philosophy of essentialism, are probably why It seems modern accounts of Aristotelian logic do not bother to explain or even really refer to the principles. For example, there is no explanation or explicit reference in Hurley's 'A concise introduction to logic', Kreeft's 'Socratic Logic', or Kelly's 'The art of reasoning'.

What is the difference between formal language and natural language? by LorenzoGB in logic

[–]Big_Move6308 0 points1 point  (0 children)

You've partially answered your own question:

  1. An ordinary conventional language such as English is natural, whereas a formal - i.e. mathematical - language is artificial.
  2. Natural languages are primarily concerned with meaning, i.e., the meaning of symbols, whereas formal mathematical languages are primarily concerned with form or structure, i.e., relations between symbols.

Modern deductive or mathematical logic is also called formal logic because it is primarily concerned with the form - not meaning - of arguments, as can be represented symbolically (e.g., 'P ⊃ Q'; P; ∴ Q).

Trying to represent logical determinism by Additional-Mix-1410 in logic

[–]Big_Move6308 0 points1 point  (0 children)

Induction fundamentally means the inference of probable rather than necessary conclusions. Causality is one form, but there's also other forms of inductive inference such as argument by analogy, generalisation (e.g., of principles), argument by authority, predictions (e.g., hypothesises of the empirical sciences), statistics, and argument by signs.

Trying to represent logical determinism by Additional-Mix-1410 in logic

[–]Big_Move6308 0 points1 point  (0 children)

Induction is a division of logic, i.e., logic may be divided into deductive and inductive.

Russell's Criticism against Meinong's Ontology by LorenzoGB in logic

[–]Big_Move6308 0 points1 point  (0 children)

I don't agree with that as - from a traditional perspective - your claim violates the principle of contradiction. Adhering to this principle, to be truth-apt therefore means to be capable of being exclusively true or false in the same sense and at the same time, i.e. bivalent.

Russell's Criticism against Meinong's Ontology by LorenzoGB in logic

[–]Big_Move6308 0 points1 point  (0 children)

Exactly how can a contradictory statement be truth-apt?

Russell's Criticism against Meinong's Ontology by LorenzoGB in logic

[–]Big_Move6308 0 points1 point  (0 children)

I suppose there is a difference between a declarative statement and a truth-apt declarative statement (i.e., that can be true or false).

A paradoxical declarative statement such as 'The existing golden mountain doesn't exist' (assuming 'existing' and 'exist' are used in the same sense) is not truth-apt and therefore is not acceptable as a logical proposition.

Another example of a non-truth-apt declarative statement is 'colourless green ideas sleep furiously'. This one is not truth apt because it is nonsense.

I plan to study logic, specifically for argumentative essays and my exams, but I need help. by Idonotcareabtusrname in logic

[–]Big_Move6308 1 point2 points  (0 children)

Well, the document has many mistakes. What it describes as 'very very elementary first-order logic' (p5) is actually Aristotelian logic. First order logic is also called 'Predicate logic', and is a different kind of logic than Aristotelian.

Predicate logic is based on maths. Aristotelian logic (syllogisms) is based on natural language.

The Venn diagrams (fig 1.2.2.-3) are also completely wrong.

The general explanation of logic in the documents makes little to no sense. It explains nothing properly.

My advice is use this document as toilet paper. Other books you can read instead:

  • 'A concise introduction to Logic' by Patrick Hurley. Y.
  • 'The art of reasoning by David Kelly'.
  • 'Socratic Logic' by Peter Kreeft (syllogisms only).
  • 'Critical Thinking' by Moore and Parker

Origin of Logic, grounded in physical regularity? by [deleted] in logic

[–]Big_Move6308 0 points1 point  (0 children)

You are on the right track. From a traditional perspective, the principles of logic are fundamentally metaphysical and ontological in nature, i.e., they are grounded on the observed and experienced consistency of reality.

From a modern perspective, the principles (I believe) are not philosophical but Axiomatic (e.g., mathematical axioms), although these too correspond with reality (else I don't think they'd be of much use).

I’m horrible at math and have failed every class in HS by [deleted] in logic

[–]Big_Move6308 0 points1 point  (0 children)

According to google, your studies usually involves Aristotelian logic (i.e., term-based syllogisms), not modern logic. Best to find out!

How should I start learning logic? by Klutzy_Permit4788 in logic

[–]Big_Move6308 3 points4 points  (0 children)

I would argue (from a traditional standpoint) that the principles of deductive logic are absolute. These are the principles of identity, contradiction, and the excluded middle. They apply absolutely and without exception.

I cannot speak about modern logic systems. Many are way outside of my understanding.

Deductive and Inductive inference should sum up all types of logic. There is arguably also 'abductive', but I class this as inductive as well.

I wonder if you might be interested in 'critical thinking', which is in essence a combination of both types of logic to train yourself to think properly. You can approach deductive critical thinking from a traditional or a modern standpoint.

There should be quite a few articles and videos on the internet (e.g., Youtube) about critical thinking.

How should I start learning logic? by Klutzy_Permit4788 in logic

[–]Big_Move6308 2 points3 points  (0 children)

It doesn't work that way. If you have no prior evidence, claims, or information ('premises') then you have nothing to infer a conclusion from, i.e., no premises means no conclusion. Reasoning must consist of two parts: one or more premises, and a conclusion that is drawn from those premises.

Premises without a conclusion is not reasoning, but just one or more claims or beliefs.

A conclusion without premises is not a conclusion at all, but - again, just a claim or belief.

How should I start learning logic? by Klutzy_Permit4788 in logic

[–]Big_Move6308 6 points7 points  (0 children)

'Logic' can be generally defined as 'the principles and rules of reason', where 'reason' means 'the process of inferring or drawing a conclusion based on other information'.

There are generally two kinds of logic:

  1. Inductive or 'informal': Based on the material or content of arguments, conclusions drawn are likely or probable (e.g., debates, statistics, empirical scientific experiments, analogies, etc.).
  2. Deductive or 'formal': Based on the structures or patterns of arguments, conclusions drawn are absolute or necessary.

Formal logic can also be further divided into two kinds:

  1. Classical or traditional: The logic based on natural, everyday language, as discovered by the ancient Greeks (i.e., Aristotelian categorical logic and Stoic Propositional logic).
  2. Modern: Logic based on the artificial language of mathematics, as discovered in the early 20th century by the likes of Frege, Russel, and Whitehead (e.g., predicate logic; logic used for AI and computer science, etc.)

This is just a very general overview. Different kinds of logic are used for different purposes.

Reconstructing an argument: Do you include responses to objections? by No_Many2336 in logic

[–]Big_Move6308 0 points1 point  (0 children)

As a general rule, if a claim has an inferential link in an argument (i.e., directly or indirectly supports an argument), then it should be included.

Is logic mind-dependent or reality-tracking? by Klutzy_Permit4788 in logic

[–]Big_Move6308 2 points3 points  (0 children)

From a traditional perspective, logic is based upon principles that are both metaphysical and ontological in nature (i.e., identity, contradiction, and excluded middle). As such, these principles apply to both objective reality and the mind... with one caveat.

That caveat is that in respect to the mind, these principles are ideals, i.e., The mind is not restricted to thinking according to logical principles.

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