I don’t buy this sort of skepticism at all. Yes, we can imagine that the external world in an illusion, but the basic flaw is (like so much in philosophy) privileging our ability to imagine something over science. Whether we can be deceived in this way is an empirical matter. Yes, you can say “everything you learned about empirical science is part of the illusion,” but all you’ve done is taken your ability to imagine an outcome and privileged that above scientific experiment. Science always trumps imagination. It is therefore, I think, impossible to formulate the skeptical thesis.
This is difficult to think about. Philosophy has given us a view of the world where perception is essentially a subset of imagination. We have pictures in our head and sometimes, if we’re lucky, they correspond to the world. The scientific view of perception, however, is that it’s just physics-as-usual. The philosophical story is an a priori psychology; if you reject the a priori, yet still buy that story, then you haven’t doubted “all the branches and leaves of that root” sufficiently. The scientific story of perception involves photons and receptors and neurons and macromolecules and all that good stuff. It can’t be used to call those things into doubt.
The correct view of all this is a (restricted) Quinean one: You have to accept the ontology of science as basic ontology. Science undermines our methods of determining other (metaphysical) ontologies (i.e., a priori reasoning); in everything we do, beginning with thought and perception, science should be our starting point. Nothing we know about thought and perception can undermine what we know about physics and chemistry and molecular biology because thought and perception are high-level areas of biology: everything we know about them is based on scientific ontology. No skeptical theses that undermines science can be constructed (science, however, can still undermine our common sense view of the world) and without skepticism epistemology reduces to neurobiology and sociology.
This is the difficult part: Even if it’s empirically possible to totally deceive somebody, to run a simulation of them inside a supercomputer and manipulate their entire life and history, we still have no reason to doubt science. Personally I doubt that this is possible. I think the whole concept of a “subjectively real” simulation is a basic error of reasoning and I doubt that cognition and memory can be so arbitrarily manipulated anyway. Regardless, if my doubts turn out to be unfounded, it will be empirical science that proves them unfounded and the argument itself will only be as strong as empirical science itself. We cannot formulate this argument based on what we can merely imagine happening to ourselves.
Descartes had it backwards. If he’d thrown out “I think therefore I am” and taken the new physics and mathematics as his starting point he would have had a very powerful form of naturalism on his hands. A naturalism that doubts common sense and accepts science as the starting point of all reason. As I like to say, there’s no distance between ourselves and the world, what happens at the retina is no more privileged than what happens at the microscope or the voltage clamp. We can just as easily take those as our starting point.
I don’t buy this sort of skepticism at all. Yes, we can imagine that the external world in an illusion, but the basic flaw is (like so much in philosophy) privileging our ability to imagine something over science. Whether we can be deceived in this way is an empirical matter. Yes, you can say “everything you learned about empirical science is part of the illusion,” but all you’ve done is taken your ability to imagine an outcome and privileged that above scientific experiment. Science always trumps imagination. It is therefore, I think, impossible to formulate the skeptical thesis.
This is difficult to think about. Philosophy has given us a view of the world where perception is essentially a subset of imagination. We have pictures in our head and sometimes, if we’re lucky, they correspond to the world. The scientific view of perception, however, is that it’s just physics-as-usual. The philosophical story is an a priori psychology; if you reject the a priori, yet still buy that story, then you haven’t doubted “all the branches and leaves of that root” sufficiently. The scientific story of perception involves photons and receptors and neurons and macromolecules and all that good stuff. It can’t be used to call those things into doubt.
The correct view of all this is a (restricted) Quinean one: You have to accept the ontology of science as basic ontology. Science undermines our methods of determining other (metaphysical) ontologies (i.e., a priori reasoning); in everything we do, beginning with thought and perception, science should be our starting point. Nothing we know about thought and perception can undermine what we know about physics and chemistry and molecular biology because thought and perception are high-level areas of biology: everything we know about them is based on scientific ontology. No skeptical theses that undermines science can be constructed (science, however, can still undermine our common sense view of the world) and without skepticism epistemology reduces to neurobiology and sociology.
This is the difficult part: Even if it’s empirically possible to totally deceive somebody, to run a simulation of them inside a supercomputer and manipulate their entire life and history, we still have no reason to doubt science. Personally I doubt that this is possible. I think the whole concept of a “subjectively real” simulation is a basic error of reasoning and I doubt that cognition and memory can be so arbitrarily manipulated anyway. Regardless, if my doubts turn out to be unfounded, it will be empirical science that proves them unfounded and the argument itself will only be as strong as empirical science itself. We cannot formulate this argument based on what we can merely imagine happening to ourselves.
Descartes had it backwards. If he’d thrown out “I think therefore I am” and taken the new physics and mathematics as his starting point he would have had a very powerful form of naturalism on his hands. A naturalism that doubts common sense and accepts science as the starting point of all reason. As I like to say, there’s no distance between ourselves and the world, what happens at the retina is no more privileged than what happens at the microscope or the voltage clamp. We can just as easily take those as our starting point.