#modus ponens

[marxist-aurelius]

joe biden has reportedly lost the mandate of heaven ‼️

[loogiclover]

you've been doing formal logic your whole life!

within a month of attending college in the Bay Area, I was exposed to the complex world that is computer science and startups. and after taking an Intro to Logic class, I realized something: every programmer who has ever written an if statement has been doing formal logic. basically, computer science is made up of something philosophers were writing down in symbols centuries ago.

and the most fundamental piece of that structure? it's called modus ponens, and you've probably also been using it your whole life without knowing it had a name!

in everyday life, it looks like this:

if I have an exam tomorrow, I should study. I have an exam tomorrow. ∴ I should study.

or in code:

if (examTomorrow) {   study(); } // examTomorrow = true // → study() runs

the if/then is modus ponens.

the formal version looks like this:

P1: if P, then Q P2: P ∴ C: Q

you give it a conditional, you confirm the first part (the antecedent), and the conclusion has no choice but to be valid.

but... there's an evil twin. there's a move that looks exactly like modus ponens but is actually invalid.

if it's raining, the ground is wet (ok so far) the ground is wet. ∴ it's raining. (not quite!)

this is called affirming the consequent. the ground doesn't have to be wet from just rain. maybe someone left a sprinkler on or a pipe burst. you confirmed Q, but that doesn't mean P caused it.

modus ponens goes: if P then Q / P / therefore Q ✓ affirming the consequent goes: if P then Q / Q / therefore P ✗

it's fun (but also not so fun) to recognize how we affirm the consequent often in real life. "if he liked me, he'd text back. he texted back. he likes me." maybe! or maybe he's polite and putting up with your double texts. confirming the result doesn't prove the cause.

once you see the structure, you can't unsee it. modus ponens really is everywhere... just be aware when your brain is running the valid version or its evil twin.

[mivones]

Thirty seven by peter stenson…youve changed me….a drop of acid in my minds eye………a blowing breeze burns

[rangi42]

Palmstroem, old, an aimless rover, walking in the wrong direction at a busy intersection is run over. "How," he says, his life restoring and with pluck his death ignoring, "can an accident like this ever happen? What's amiss? "Did the state administration fail in motor transportation? Did police ignore the need for reducing driving speed? "Isn't there a prohibition, barring motorized transmission of the living to the dead? Was the driver right who sped…?" Tightly swathed in dampened tissues he explores the legal issues, and it soon is clear as air: Cars were not permitted there! And he comes to the conclusion: His mishap was an illusion, for, he reasons pointedly, that which must not, can not be.

"The Impossible Fact", by Christian Morgenstern (translation by Max Knight)

“One man’s modus ponens is another man’s modus tollens.” — Fred Dretske

[odkladiste]

a bit of logic thrown upon your holy book

Bible advocates genocide and slavery. Option 1) If everything in Bible is true, genocide and slavery are sometimes desirable. Option 2) Genocide and slavery are never desirable, therefore not everything in Bible is true. Which one will you choose?

[s33]

Proposed: The Materialist-Mechanist-Functionalist view follows a modus ponens line of reasoning that says:

All phenomena are ultimately reducible to objective mechanisms

Subjectivity is a phenomenon.

Therefore subjectivity must be produced by an objective mechanism.

The Idealist-Immaterialist view follows a modus tollens logic:

Subjectivity is not an object or mechanism.

Subjectivity is a phenomenon.

Therefore not all phenomena are objective mechanisms.

If we take the mechanistic view a step further, and ask 'If all things are objective':

subjectivity must be objective.

dualism is objectively true.

or

Subjectivity is produced by objective processes but not objective itself

emergence is true.

emergence is not an object or mechanism

emergence is a phenomenon

therefore not all phenomena are objective, and 1. is false.

emergence is subjective

emergence could be subjectivity itself

If we take the idealistic view further, we can say 'If all things are subjective'

Objectivity may be relative.

Dualism may be relative.

Objectivity may be produced within subjective consciousness but not objective itself.

Local objectivity may be relative to a greater subject or greater context of immaterial experience.

Emergence is redundant.

[philosophiend-blog]

Bora estudar um pouquinho? 

[myfuckingkhagne]

Quand tu révises la spé philo.