Question about logic sentence

[Austin Duggan]

I posted this in the new members section earlier today. I have two questions. First, does this make sense:

Actions t occur if and only if there is some substance of the form x with property E. If a substance I commits action t, then I is of form x. Therefore I has property E.
And also, is it equivalent to the logical statement below? Thanks!

[Nocturne]

Austin Duggan,

I do not think that your formula is valid, though I am unfamiliar with how it is presented and so perhaps have misunderstood. It seems to me quite unclear what you are quantifying, and why t is used as a variable, proposition and a predicate. I suspect that what you intend to say can be formalised more simply. However, I am primarily interested to learn more about the problem which you are trying to solve and why you think that this formula is important, and so any indulgence of my interest would be appreciated. (It might also help me understand what you are trying to say in your formula).

Regards,
Lee

[simon]

I confess I have no idea what you are trying to represent, though I'm a little dubious about the logic. My question is "why the question?"

There are a lot of scenarios that might fit that logic though. If you're interested in the nature of matter ask outright ;o)

[Aristoddler]

the formula means nothing without knowing what the symbols represent.

what is the action?
if A=dying, then everything else is moot, since it will all =0
if A=birth, then everything else is also moot, since it has yet to = 0

the action must be something objectified since it has bearing on the rest of the formula.

basically the formula is unfinished.

[Austin Duggan]

I've probably bungled this severely. I'm just trying to translate cogito ergo sum into logic for something I'm writing. Let me put it this way:

Thinking (t) occurs if and only if there is some substance (x) that Exists (E). If I think, then I am of form x. Therefore I Exist.

Does that make sense?

I've never taken a class in logic, or even anything past college algebra for that matter. I'm sure that's apparent. I read Daniel Velleman's book Prove It, along with some other classics. But of course, I've never had any homework, and my writing rarely requires formal logic. Still, I'd like to know it better. So any help will be greatly appreciated.

[Aristoddler]

t=(x=e)

if t/x=e, then t=e

yes that's right

rocks cannot think, although they exist.
therefore although t=e, e does not necessarily = t.

[Austin Duggan]

Wait....so my logic does make sense?

[Aristoddler]

lol, yes.

Just...not in a linear sense.

[Austin Duggan]

Awesome. Thanks for checking it. Let me know if there's any way to clarify or simplify the statement.

[Nocturne]

Austin Duggan,

No worries. I have never taken a class in logic or algebra, but neither is particularly difficult once you learn to speak the language. I am, however, confused as to what Descartes 'cogito ergo sum' argument has to do with the problem of free will, but then I am not entirely clear what the problem of free will is, so perhaps it is to be expected. Personally, I think that Descartes argument is best understood as a sceptical attack upon evidence and self-evidence. For example, take the following three existential statements:

1. There exists a black raven
2. There exists a perception of a black raven
3. There exists a perception of a perception of a black raven

The first statement is about ravens, the second statement is about perceptions, and the third statement is about perceptions of perceptions. In other words, each existential statement quantifies over a different domain, and not one can be deduced from any other. That is, it does not follow from the existence of a perception of a black raven that there exists a black raven, and it does not follow from the existence of a perception of a perception of a black raven that there exists a perception of a black raven. In other words, evidence and self-evidence do not imply that what is being perceived actually exists. However, no matter our scepticism or how far we push this regress, the existence of a perception is always assumed. In other words, there is something perceiving, thinking, existing.

It should be noted for those that consider it a problem that the 'cogito ergo sum' argument exemplifies a form of question begging, however, so does every valid argument and, for that matter, many invalid arguments, too. That said, I have yet to hear or read a refutation of it.

Regards,
Lee