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Logic behind theories and perception.

  1. Jul 20, 2009 #1
    Jun3-03, 03:02 PM

    "... logic is not an attribute of the universe, but instead is our means of understanding the universe, while the universe itself has nothing to do with logic. For expample, imagine a person who for the first time in his life is exposed to Heisenberg's uncertainty principle. To that person, until he comes to accept QM, the universe would seem illogical. Notice the word seem, as logic only exists in human perception and is not a universal fact."

    Some thoughts (I'm totally in the woods here.:):

    a. If this is a true statement - I am asking how can we ever define universe to ourselves with human logic?

    b. Every physical theory is based in logic i.e. human perception while they have nothing to do with universal facts?

    c. From where and which point does this human logic emerge (i.e. condradicting that human him-/herself is a part of universe)?

    d. Is it a universal fact that logic only exists in human perception?

    e. logic (while nothing to do with universal facts) = human means (or even maybe grammar?) for understanding the universal facts? !!

    The thread I'm referring is to be found here:

  2. jcsd
  3. Jul 20, 2009 #2
    I think this is where your problem lies. If by this, you mean 'actual things that exist', then you are confusing ontology(matters of existense) with epistemology(matters of knowledge).

    A fact, is a bit of knowledge, its not something that exists 'out there'.

    The 'actual world' around us is not what 'we experience'. So talking about 'facts', bits of knowledge, as universals, is really nonsense.

    Logic is about making generalizations. Human logic is derived from human experience, which is a function of our interaction with the world around us. So, yes, human logic is a human invention, which is distinct from, 'the way the world works'.

    Logic can describe the universe, but its always a generalization, an approximation. No description of the universe would describe the universe in full detail, but would just describe what we know about the universe. A description is not the same as the thing it describes.
    Even a theory of everything, would only be a human model of what is, not what actually is.
  4. Jul 20, 2009 #3
    The KEY to "logic" in the universe is causation. Without it, logic as we know it, can't exist. Since we are living in a causal universe, the universe is itself logical and comprehensible. Hence the above statement that the universe has nothing to do with (human) logic is wrong.
  5. Jul 20, 2009 #4
    So the key to logic... is circular reasoning.
    Good to know.
  6. Jul 20, 2009 #5

    What circular reasoning? We don't know why the universe is causal in nature. Maybe you think you know why, but you are wrong - you don't know.
  7. Jul 20, 2009 #6

    From the Big Bang. Since 10^-43 sec. after the BB, the universe has continuously been playing out under the cause-effect rule. Everything, from love through planets, cars, humans, etc. all the way to logic started out at the BB in a 14 billion year old chain of events. This is possible because our universe is made of cause-effect interacting particles.

    Having said that, a 'universe' of non-interacting particles would be both incomprehensible and illogical as far as human logic is concerned. Maybe such universes(born out of giant quantum fluctuations) are ubiquitous but since we can neither perceive nor interact with them, they will forever remain "non-existent" to cause-effect bound creatures made of interacting particles like us.

    But i wonder if the cause-effect logic is the only possible logic that there could be. Clearly our brains aren't wired to understand uncaused events, but it would be egocentrical to think we humans are the end-all be-all as far as logic is concerned.
  8. Jul 20, 2009 #7


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    You're raising a good question. As JoeDawg says, first point is to accept that the mind is in a modelling relationship with the world. We construct ideas that seem - as revealed by a prediction and measurement feedback loop - to model the world.

    Logic is then our internal model of causality - it is our very general level story on why anything happens.

    Now the world does seem lawful and regular in its behaviour. It has pattern. And humans did build up an image of causality, of logic, from long observation of those patterns.

    But where things get tricky is that humans could only see reality from the vantage point of a particular (classical) scale. Just as importantly, humans were modelling the world with a particular purpose - to survive and thrive via sociology and technology. So the logic we created was slanted/shaped/constrained by these kinds of biases.

    It was not the logic of THE world in some perfect way, but the logic of OUR world. So a utilitarian logic.

    In philosophy, you can study the development of the Western idea of logic, coming to understand its necessary presumptions, and thus the ways in which it is "unreal". The law of the excluded middle for example. And you can learn about logics that try to fix these things - the work of CS Peirce in particular.

    So our logic is a model, it is not monolithic (there are variants and even very different models possible), and it is still a work in development. It can hope to approach the totality of reality more closely.

    Bringing QM "into the fold" would be a big step forward for logic - our model of causality. And I think a systems science style approach to logic would be the way.

    Systems science is an expanded logic in that it is holistic, bootstrapping, observer-based, allows for downward causality, treats initial conditions as creatively vague, etc.
  9. Jul 20, 2009 #8
    So You would say that at the current state of evolution human species DNA is capable of producing logic to be utilized maybe more in its surviving as a species than finding out universal facts? Maybe causality and "this kind of" (there can surely be other kind of reasoning strategies?) logic derived from that is the only way we can try to comprehend universe at the current state.
    I would be afraid of course saying that the current reasoning strategy is a dead end what comes to truly understand the universe to find the ultimate truths about it. Maybe our reasoning is destined to evolve just like everything else in this seemingly dynamic ever changing universe.
  10. Jul 21, 2009 #9


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    The point really is that there is no "truth" without a purpose also. We frame reality in the ways we find most useful to us.

    So while it is normal to talk about knowing the truth of reality as if it were some disinterested, abstract, exercise, the systems view would say instead no modelling can exist - or even make sense - in a disinterested fashion.
  11. Jul 21, 2009 #10
    Our mind is built upon determinism. The whole premise of logic is that we are able to understand a process and event in the universe.. Whether or not this interpretation of the events tell us anything about the actual event, is up for debate.

    I think in the macroscopic world, our understanding does tell us a lot about the universe.
    The logic, but also our emotions and thoughts tell us what something means, and how it works, and that this reflects upon the event.
    If we are certain a glass will fall to the ground because of gravity, then it is a model, but it is also true..
    I think that because our models and logic holds true and we can use them in reality, it tells us that we aren't completely wack and that I think reflects on whether or not logic is manmade or not.

    Logic by itself may be man made, but there is something universal there too.. If we define something logical as just being a process, then that process MUST be deterministic and thus logical, and thus it is universal, the concept of logic will work in any universe/type of existence that is not complete chaos.
    There may be completely different levels of function and ways of doing things, but the process of applying logic is that it has a deterministic step by step event chain.
    These event chains can of course be layered on top of each other, happen simultaneously and even interact with each other, but the determinism underneath is 100%.
  12. Jul 21, 2009 #11
    While a cause-effect deterministic universe might appear quite comprehensible, sentient beings like us require more than a set of causal interacting particles to exist the way we do(logic cannot exist by itself without someone/something to observe and make sense of it). Our existence pre-supposes a set of governing laws that would frame our development from an RNA molecule to a state like the one we are witnessing now, i.e. a state when we are mentally developed to ask deep questions about reality and existence. These laws that are governing life aren't the same laws we are familiar with from physics(i.e. the particles in question aren't only interacting, they are interacting in very precise and specific guided ways). But one may ask - why are the laws of the universe like they are? Why are they so permissive to the emergence of something so complex as life in this deterministic comprehensible cause-effect universe?
    Last edited: Jul 21, 2009
  13. Jul 21, 2009 #12


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    Another way to look at this is that global-scale laws do not "determine", rather they constrain. They act downwards on the local scale to suppress action. And then what actions they cannot suppress are thus - logically! - free to happen. They are precisely a local degree of freedom, or inertia (a local symmetry in fact).

    So this view of causality (this model of logic that comes from a systems perspective) would answer that laws are always permissive of what they can't see to suppress. In trying to stop as much as possible happening, a few things will then definitely happen.

    This then would lay the ground for a dissipative structure or entropy degrader approach to the question. Life arises as order that speeds the universe's descent into the "chaos" of entropy - fufiling the mandate of the second law of thermodynamics.

    Actually the second law is one that is framed in terms of global constraints rather than localised determination. It does reflect the systems view.
  14. Jul 21, 2009 #13

    Laws of the universe, as far as my logic is concerned, are the in-built inherent properties of particles and quantum fields that allow/guide their behaviour in constructing reality the way we see it.
  15. Jul 21, 2009 #14


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    But that is still just one way of seeing it. Useful for some purposes perhaps. But not, I would argue, appropriate for the task of modelling the universe as a system.
  16. Jul 21, 2009 #15
    But if the universe is deterministic, what is there to suppress?
    Determinism implies to me a definite process for events, but your post implies that these processes might happen in other ways but are suppressed by something.
    How can this be?
    The only way I can think of it is that these constraints also have their own rules, along with the processes, so that there really aren't any constraints they are just part of the determined chain of events..
  17. Jul 21, 2009 #16


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    I don't think the others have addressed the real issues here. Your A-E are written with extremely poor grammar, but I'll try to address them collectively, then individually:

    Logic in science is a method/tool by which facts are interpreted and understood.

    a. My bolded statement above relates to your quote that "logic is not an attribute of the universe, but instead is our means of understanding the universe, while the universe itself has nothing to do with logic...." But the two halves of that are not mutually exclusive. In fact, it is helpful to examine the universe using tools that follow the universe's way of working. In other words, logic works as a method for understanding the universe because the universe is logical.

    b. That implies a misunderstanding of how logic works. Logic starts with facts and assumptions. Logic then draws conclusions/interpretations from those facts. So yes, science is based on universal facts (that really should be obvious...).

    c. I can't make heads or tails of this. Are you implying that our perceptions are not representative of reality? We're not living in the Matrix and even if we were, it wouldn't have any effect on how science works. Perception = reality. Or at least we can assume it does because we don't have anything else to go on and it has worked so far.

    d. No. It can be shown that the universe behaves logically. It follows the same rules as human logic. One might even argue that human logic is derived from the logic of the universe...

    e. I think I know what you are looking for, but "grammar" isn't it. Connect it to math: Vocabulary and grammar are how the numbers and symbols are defined and fit together into coherent thoughts. Logic is what those thoughts represent. Math is the exploration of a form of logic.
  18. Jul 21, 2009 #17


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    Could you explain what you mean by that? It doesn't make any sense to me.
  19. Jul 21, 2009 #18
    Until it can be proven that anything happens outside the consciousness there doesn't seem to be much point in trying to prove that logic is a component of the universe. We assume it is because nothing makes sense if we don't, and we like things to make sense. All that can be said with any level of certainty is that logic is a component of consiousness.
  20. Jul 21, 2009 #19


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    You have that precisely backwards. Not only is there no reason not to believe our perception isn't reality, it doesn't matter if it is or isn't. It has no effect on how science works or how successful it is. So we may just assume it to be true and be done with it.
    Try it from the other side: assume what you say is true. Where does that take you? Since we know only what we perceive, assuming our perceptions are wrong is a dead end. It is inherrently unprovable either way. We can't explore that issue because we can't remove our "preception glasses".
  21. Jul 22, 2009 #20
    You are mostly correct. We must assume our perception is real if we are to learn anything about what we can percieve of the universe. There is a philosophical reason to believe our perception isn't reality, but that doesn't get us anywhere in understanding what we percieve scientifically.

    The only alternative to not assuming the universe has somewhat of a logical nature is to sit in the closet and be ignorant of any knowledge. The reality could be somewhat different, but that is pure speculation and not conducive to understanding.
  22. Jul 22, 2009 #21
    No, the universe appears, for the most part, to follow the logical structure, that humans have been able to develop and derive from mental experience.

    Observational errors, mysterious occurances and even things like Quantum Mechanics and Dark Matter are examples of where human logical structures have failed. Logic is a series of generalizations based on what we can only optimistically call: limited observation of what we hope is a consistent, and will remain a consistent, universe.This is not to say that we might not be able to develop a logic that includes these things.

    The universe is what it is, we can describe some of it with logic, a system we developed by observing patterns in the universe. But the fact we have observed patterns doesn't mean those patterns have any explicit relation to the universe. They are mental constructs and useful ones, but so is thinking of tables and chairs as solid, even though we know from science, they are mostly empty space. And science has shown over and over, that it is dangerous to rely too heavily on the tentative conclusions we may come to through experience.
    Science may begin with facts, but logic does not. Logic begins with premises, which are simply assumptions. An assumption need not be correct or factual. Just because something is logically consistent doesn't mean it has an analog in experience.
    Again logic is dependent on premises, there are lots of logical constructs which conflict with observation. So saying the universe behaves logically isn't really saying much.

    Logic is a system derived from experience and is therefore useful when dealing with experience. But that doesn't mean our experience or the lessons we have derived from it have any direct relation to 'what is out there'. The most we can honestly say is that the logic we have derived from experience has been useful in dealing with experience.
  23. Jul 22, 2009 #22
    I see logic simply as a system that is coherent and deterministic, and since our thoughts are capable of creating internal worlds, our internal worlds are completely logical, but they may not be true.
    But reality still has to be logical, because anything else would result in something incomprehensible..
  24. Jul 22, 2009 #23
    Reality doesn't have to be anything we think it is.
    And quite a lot of it is incomprehensible.
    Ever tried to predict the weather?
  25. Jul 22, 2009 #24


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    The universe would not be treated as locally deterministic in this view. That is an axiom of a different model. Though agreed, that it is the Standard Model of logic!

    So what I am talking about is a way to get local action that looks determined by its own local, substantive and internal properties - the way we think an electron has a property like negative charge - but is instead achieved by a different method. That is top down constraint.

    To take a rough analogy, think of the way an engine cylinder constrains the explosion of the gas/air mixture. The explosion has the potential to expand in all directions. But those other directions are suppressed and all the action has to be expressed in just the unsuppressed direction - so pushing the piston.

    If you then take more interesting examples like the quantum zeno effect, you can see something of the same as microphysics.
  26. Jul 22, 2009 #25


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    Wavejumper was saying there is only one causality he believes in, one based on bottom-up construction from atoms with properties. This is the Standard Model as I acknowlege. It involves a number of familiar ingredients - atomism, mechanicalism, monadism, locality, determinism.

    But in systems science - which is a pretty broad church itself, so contains another set of ideas, not yet so well integrated - there would be a second general model of causality. One designed for explaining systems and so likely to be better for explaining the universe as a holistic system (rather than as a bottom-up construction).

    So the argument has a series of steps. First, the recognition that we are in a modelling relation with the world. Second that our general model of causality is what we call our "logic". Third that there are then possibly a number of candidate logics (especially as we can have different purposes, different tasks, and so have reason for different tools).

    Many people here understand the first two things but have not come across the idea that there could be more than one logic. They tend to take the platonic view that logic is perfect reasoning and so there can only be one example of a perfect thing. But you can doubt your reason just as much as you can doubt the world if you are being the kind of sceptical scientist we all claim to be. And then as a scientist, you would get on and work to minimise that doubt via the effectiveness of your modelling - the success you have in using a chosen logic to predict what you can observe about the world.
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