Logic: Inverse, Converse, & Contrapositive

[StealthParticipant 5330]

More memories from my logic class.

Let’s take a true statement: All dogs are animals.
Let’s rewrite it as an if/then statement: If it is a dog, it is an animal.
Let’s symbolize it with variables (like algebra):
A = being a dog,
B = being an animal,
If A, then B.
We can write this as [A—>B].

An INVERSE statement [~A—>~B] negates both sides of the if/then proposition. In this case, the inverse of our original statement would be “If it is not a dog, it is not an animal.” It can be written with our math-like variables using that squiggly line to mean “the inverse of.” An inverse statement DOES NOT LOGICALLY FOLLOW from our original statement; this can be shown by pointing out that a bird is not a dog, but is still an animal.

A CONVERSE statement [B—>A] flips the terms of the if/then clause. “If it is an animal, it is a dog.” A converse statement also DOES NOT FOLLOW from a true original statement.

A CONTRAPOSITIVE statement [~B—>~A] both inverts and flips the original statement to say, “If it is not an animal, it is not a dog.” The contrapositive is the only form that DOES FOLLOW an original statement.

—————-
These rules apply when rearranging a statement to yield an equally true statement. I should point out that inverse and converse statements might occasionally be true for other reasons, but they don’t logically follow based on the original statement.

Also, the original statement is presumed to be true, but in statements of opinion, or even false statements, the rules are the same.

"Once you’ve taken care of the basics, there’s very little in this world for which your life is worth deferring." -David Hansson. "It’s not when women are mean or nasty that anything is out of the ordinary. It’s when they are NICE to you that you have to be on high alert..." -Jackinov.

[StealthParticipant 5330]

(deleted)

"Once you’ve taken care of the basics, there’s very little in this world for which your life is worth deferring." -David Hansson. "It’s not when women are mean or nasty that anything is out of the ordinary. It’s when they are NICE to you that you have to be on high alert..." -Jackinov.

[StealthParticipant 5330]

Some practice examples:

If a female sex partner consented to sex, then her male partner is not guilty of rape.

Inverse: If the female sex partner did not consent to sex, then the man is guilty of rape.
Converse: If the male partner is not guilty of rape, then the female sex partner consented to sex.
Contrapositive: If the male partner is guilty of rape, then the female partner did not consent to sex. (Logically follows)

If she is a woman, then she is a narcissist.

Inverse: If she is not a woman, then she is not a narcissist.
Converse: If she is a narcissist, then she is a woman.
Contrapositive: If she is not a narcissist, she is not a woman. (Logically follows)

If you save more money than you spend, you will grow rich.

Inverse: If you don’t save more money than you spend, you will not grow rich.
Converse: If you’ve grown rich, you saved more money than you spend.
Contrapositive: if you’ve not grown rich, you didn’t save more money than you spend. (Logically follows)

"Once you’ve taken care of the basics, there’s very little in this world for which your life is worth deferring." -David Hansson. "It’s not when women are mean or nasty that anything is out of the ordinary. It’s when they are NICE to you that you have to be on high alert..." -Jackinov.

[harpo-my-“SON”Participant 2410]

KISS= Keep It Simple Son.

Biology 101 says there are two kingdoms of
life on earth.

Animal kingdom and plant kingdom.

Why complicate it?

I once stated that human beings are animals and
had a lady try and argue with me.
She insisted that humans are something
other than animals.
She went on to say we are somewhat better
than animals.

I pointed out that Humans are the only
one of God’s creatures that can harbor
evil motives and bad intentions.

I am certain that I am not a plant.
By simple process of elimination I
determined that, I must be part of the animal
kingdom.

The best and the worst part of the animal kingdom
is the Human being.

Love and respect to all

I was bound to be misunderstood, and I laugh at those who misunderstand me. Kind mockery at the well intentioned, but unfettered cruelty towards those would be prison guards of my creative possibilities. This so as to learn as much from misunderstanding as from understanding. Taking pleasure in worthy opponents and making language fluid and flowing like a river yet pointed and precise as a dagger. Contradicts the socialistic purpose of language and makes for a wonderful linguistic dance, A verbal martial art with constant parries that hone the weapon that is the two edged sword of my mouth.

[OldBillParticipant]

harpo-my-“SON” wrote:

Biology 101 says there are two kingdoms of
life on earth.

There are three actually; Archaea, Bacteria, and Eukaryota.

But don’t let anything like facts or even reality intrude on your “thinking”.

Animal kingdom and plant kingdom.

The plants and animals you’re gibbering about both belong the to the Eukaryota kingdom.

Why complicate it?

It’s not complicated at all or, more accurately, it’s not complicated for those who aren’t mentally ill.

How long are the orderlies going to let you use the computer in the quiet room this time?

Do not date. Do not impregnate. Do not co-habitate. Above all, do not marry. Reclaim and never again surrender your personal sovereignty.

[Faust For ScienceParticipant 22521]

Stealth wrote:

Let’s take a true statement: All dogs are animals.

I value dogs above most animals and many people.

You raise a dog right the dog will be a loyal, loving creature whom will give their life for you, or will mourn your passing. Most people will not do either of those actions for you.

[StealthParticipant 5330]

With logic, it’s not really the content of an argument that matters… What matters is its form.

"Once you’ve taken care of the basics, there’s very little in this world for which your life is worth deferring." -David Hansson. "It’s not when women are mean or nasty that anything is out of the ordinary. It’s when they are NICE to you that you have to be on high alert..." -Jackinov.

[Ranger OneParticipant 16836]

harpo-my-“SON” wrote:

She went on to say we are somewhat better
than animals.

I pointed out that Humans are the only
one of God’s creatures that can harbor
evil motives and bad intentions.

I watched a video of seals raping penguins; I’m pretty sure their motives were not good.

Chimps and dolphins have both been known to engage in gang-rape.

All my life I've had doubts about who I am, where I belonged. Now I'm like the arrow that springs from the bow. No hesitation, no doubts. The path is clear. And what are you? Alive. Everything else is negotiable. Women have rights; men have responsibilities; MGTOW have freedom. Marriage is for chumps. If someone stands in the way of true justice, you simply walk up behind them and stab them in the heart-R'as al Ghul.

[PistolPeteParticipant 27143]

WOW Stealth great analysis, it was like a blast from the past in my old college days, but when it comes to women you are thinking too much. So lets try it again: Proposition A: All women are toxic destructive c~~~s.
Proposition B:….doesn’t seem to be a proposition B, prop A seems to have it covered…period.

[OldBillParticipant]

harpo-my-“SON” wrote:

I pointed out that Humans are the only
one of God’s creatures that can harbor
evil motives and bad intentions.

I missed this part because I was too busy laughing at the other parts.

During her decades long observational research of a Gombe park chimp troop, Jane Goodall watched a mother and daughter pair of chimpanzees stalk, kill, and eat infants belonging to other females. At first Goodall was so disturbed by the behavior that she broke scientific protocol and interfered on a few occasions to prevent killings. She reverted back to a purely observational mode and watched the mother daughter pair act as cannibalistic serial killers for nearly two decades until the mother in the pair died.

While Goodall observed it first, other researchers have since witnessed similar behavior in other troops of chimpanzees.

So much for your childish beliefs that only humans can be evil.

Do not date. Do not impregnate. Do not co-habitate. Above all, do not marry. Reclaim and never again surrender your personal sovereignty.

[PistolPeteParticipant 27143]

OldBill wrote:

So much for your childish beliefs that only humans can be evil.

Calm down OldBill, I think what Harpo meant was that only human beings can understand/appreciate the moral quality of their actions. Animals have no conception of good or evil, only people do hint hint–that is what separates us from the animals.

[StealthParticipant 5330]

Or we could talk about dogs and monkeys if you pre-furrr

"Once you’ve taken care of the basics, there’s very little in this world for which your life is worth deferring." -David Hansson. "It’s not when women are mean or nasty that anything is out of the ordinary. It’s when they are NICE to you that you have to be on high alert..." -Jackinov.

[MorpheusParticipant 2177]

Stealth, can you recommend some good books on logic?

[StealthParticipant 5330]

Morpheus wrote:

Stealth, can you recommend some good books on logic?

Any logic textbook should cover the basics. There are also websites. The rules are the same everywhere. My college used two books: one was Critical Thinking by Moore & Parker, and the more advanced one was Understanding Symbolic Logic by Klenk.

"Once you’ve taken care of the basics, there’s very little in this world for which your life is worth deferring." -David Hansson. "It’s not when women are mean or nasty that anything is out of the ordinary. It’s when they are NICE to you that you have to be on high alert..." -Jackinov.

[OldBillParticipant]

PistolPete wrote:

I think what Harpo meant was that only human beings can understand/appreciate the moral quality of their actions.

You’re not giving animals enough credit and there’s an increasing amount of research that suggests animals aren’t the dumb, mindless, soulless brutes we’ve long thought them to be.

As for Harpo “meaning” anything, that’s a stretch. While he has his periods of lucidity, there’s always an undercurrent. He’s like a top which is just about to wobble or a chaotic system just about to jump to a new state of seeming stability.

Do not date. Do not impregnate. Do not co-habitate. Above all, do not marry. Reclaim and never again surrender your personal sovereignty.

[PistolPeteParticipant 27143]

Wait a second…I never said animals were dumb, mindless brutes…soulless? unknown. Now people on the other hand I know plenty of people who are dumb, mindless brutes—and they are soulless if female. HA HA. Which reminds me–do you know why Jane Goodall spent all those years with the chimps/gorillas? She was hoping one of them would lower himself to bang her—she dies unfulfilled. Maybe if she had put a banana up her cootch.

Yes I know Harpo can be a little esoteric but I find that if I read his stuff two/three times I begin to get the meaning. I’ve found that often he has several or more meaning(s) layered in so it is a little tough sometimes to untangle.

[MorpheusParticipant 2177]

Stealth wrote:

Morpheus wrote:

Stealth, can you recommend some good books on logic?

Any logic textbook should cover the basics. There are also websites. The rules are the same everywhere. My college used two books: one was Critical Thinking by Moore & Parker, and the more advanced one was Understanding Symbolic Logic by Klenk.

My next purchase.

[ZarathustraParticipant 2246]

Great post I love it! I studied 3rd order logic in a graduate program but my mind is so mushy and underused these days this was a great refresher. A few weeks ago I was trying to remember all those rules and was going to look them up but I didn’t get to it.

I can’t seem to figure out how to send messages to individual members so since we are on the topic of Philosophy I was going to recommend Alvin Plantiga to any MGTOW with a theistic bent (Hint hint Pistol Pete). He’s a great modern philosopher who has taken many theological and classical ideas and updated them with a modern bent – especially St Agustine. His reliability theory of epistemology is the position I myself take.

https://en.wikipedia.org/wiki/Alvin_Plantinga

Anyways a little technical but a great writer who really translates a lot of theistic ideas to a modern perspective.

Thanks again stealthy!

[ZarathustraParticipant 2246]

OldBill wrote:

PistolPete wrote:

I think what Harpo meant was that only human beings can understand/appreciate the moral quality of their actions.

You’re not giving animals enough credit and there’s an increasing amount of research that suggests animals aren’t the dumb, mindless, soulless brutes we’ve long thought them to be.

As for Harpo “meaning” anything, that’s a stretch. While he has his periods of lucidity, there’s always an undercurrent. He’s like a top which is just about to wobble or a chaotic system just about to jump to a new state of seeming stability.

On some level my dog, Nietzche, must comprehend morality. He certainly knows when he is done something wrong and will display signs of guilt and offer contrition when doing wrong.

He may not understand morality in a deeper sense but he certainly knows what I deem to be “good” and “Bad” behaviour.

As Nietzche said a dog is the only creature that knows its God.

[PistolPeteParticipant 27143]

Zarathustra wrote:

On some level my dog, Nietzche, must comprehend morality. He certainly knows when he is done something wrong and will display signs of guilt and offer contrition when doing wrong.

He may not understand morality in a deeper sense but he certainly knows what I deem to be “good” and “Bad” behaviour.

As Nietzche said a dog is the only creature that knows its God.

OK got me! my cat knew when he did something wrong to—difference is he enjoyed doing wrong things. He thought it was funny.

[Author]

Posts