Setting external world skepticism aside for a moment, suppose I'm about to roll a die. Now there are two possibilities: it will come up 1 or it won't. If I reason as you did, I will conclude that the probability is 1/2 that the die will come up 1.

Something has gone wrong here. For one thing, we can't get the answers to probability questions just by counting. There are many ways to slice up the space of possibilities, and if we use your rule, the answer we get will depend on how we do the slicing. This is a well-known problem, and there is no simple fix. But there's another problem: the probabilities here aren't chances. They are degrees of belief. Even if we thought (though we shouldn't) that the right way to slice things up is that our experience has an external source or it doesn't, without adding nothing more fine-grained, we don't have to agree that the two possibilities are equally probable. You say "it seems to me that both possibilities are equally likely." It's worth wondering whether you really know your own mind on this question, but even if you do, that carries no weight for the rest of us.

Some people call these degrees of belief personal probabilities, so let's follow suit. My personal probability for the proposition that none of my experiences have an external source is infinitesimal. I give that possibility essentially no credence at all. That's not a justification for rejecting external-world skepticism. It's a confession of my incredulity.

Now you might think that any philosopher who admits this should turn in their union card. Interestingly, this would mean that many professional epistemologists would have to look for a new profession. Near as I can tell, most philosophers who work in theory of knowledge aren't much tempted by external world skepticism. They assume that there's an external world and that we know things about it. The goal is to understand the structure of that knowledge.

You write "If I have no access to the external reality, how am I supposed to establish what is convoluted and what is not?" Leave aside the question of whether this is the right way to think about judgments of what's convoluted. If there is an external world of more or less the sort we usually think, then you do have access to it. You see it, hear it, touch it, taste it, smell it. The fact that you doubt whether your experiences are veridical doesn't show that they aren't caused by something outside your mind.

One of the problems with radical skepticism is that the skeptic typically is looking for something we couldn't have (certainty about contingent matters) and sees the fact that can't have it as a reason to think the skeptical hypothesis is credible. But even if we talk in terms of probability (not that I actually think it will help us much to do that here), not having probability one is not the same thing as not knowing anything. I know things about the world if I believe them, they're true, and I'm actually in contact with things in the right sort of way. I can believe things even while admitting I could be mistaken, the things I believe could be true, and what's responsible for my beliefs could be the external world, more or less as I believe it to be. Given the notion of proof the skeptic usually has in mind, I can't prove that I have any such knowledge. But (to repeat my confession) I don't see this as anything I should lose sleep over. You think solipsism or something like it is as likely as not. I don't have the slightest inclination to agree. And though this is hardly a proof of my view, my view has the advantage of freeing us up to think about questions that seem to me, at least, to be a lot more interesting and productive.

With matters of etiquette, such as which hand to use for the fork, or matters of personal preference, such as which wrist to use for one's watch, I don't think "Why?" questions are intellectually substantial enough to be worth asking more than once or twice. But philosophical and scientific questions are intellectually much more substantial, much deeper. There it makes excellent sense to keep asking "Why?" questions for as long as those questions remain well-posed. You're right that we don't want a loop -- a circle -- of "Why?" questions, because in that case a question reappears after it has already been adequately answered. But a loop is different from a regress of questions, which may be finitely long or indefinitely long. On whether an indefinitely long regress is always something to avoid, see this SEP entry.

I think that you and those you see as your opponents may simply be talking past each other. You define consciousness so that being conscious logically guarantees being aware of your surroundings. In arguments about external-world skepticism, consciousness has traditionally been given a weaker definition, a definition that doesn't logically guarantee being aware of your surroundings. In the classic evil demon scenario, your conscious mental states are caused by the evil demon and not by your surroundings (not even indirectly). You're conscious -- that is, you're not in the midst of an experiential blank -- but your conscious states are unreliable indicators of your surroundings. Sometimes the term "perception" is used to distinguish conscious states that reliably represent the environment from conscious states that represent it unreliably .

I hasten to add that it takes a lot of argument to get from (1) the admission that consciousness can be inaccurate to (2) the conclusion that we never achieve external-world knowledge via our conscious states. I don't find any of those arguments compelling, but even so the refutation of skepticism isn't as easy as alleging that skeptics misuse the word "consciousness."

Fascinating questions.

The view that no one can know anything does not seem self-defeating to me. You think this version of global skepticism defeats itself because it implies that the view itself is unknowable. But why does this defeat the view? Even if we cannot know the view to be true, there still may be sufficient reasons to believe it.

Nevertheless, suppose you are a global skeptic who wishes to maintain that you know the truth of global skepticism. You believe global skepticism and its implication that you do not know the truth of global skepticism. Does the fact that you do not know the law of non-contradiction give you a reason to affirm that you also know global skepticism is true?

I do not see why. To be consistent in your global skepticism, you should admit that you don't know whether there are any true contradictions. But that doesn't give you a positive reason to believe that when you say "I know no one can know anything," it is both true and false.

Great questions. An initial observation: Fromm's view of love seems compelling, though I am uneasy about his claim that love is not a feeling. It seems that one might have discipline, patience, faith... and care for another person, but without FEELINGS (the emotions) of delight in the one you love and sorrowing when the beloved is injured, I am not sure you would have a case of love. So I think Fromm's claim that love is not a feeling, but a practice, is open to challenge. Maybe he might have made the point that love is not MERELY a feeling.

Over to your first question: Because there seem to be very few evident perfect persons (even Gandhi had his faults), I think your (excellent) question would probably best be posed in the philosophy of religion. Classical Judaism, Christianity, Islam and theistic Hinduism believe in the divine (God, Allah, Brahman) as a perfect, maximally excellent reality. I suggest love of the divine in such practices would include the cultivation of awe (or praise or worship or delight) in response to the divine and the pursuit of what these faiths identify as sacred: loving other persons, pursuing justice and mercy, being good stewards of creation / the natural world. This would seem to require discipline, concentration, patience, faith and the overcoming of narcissism. Viewed this way, I suggest that one can love a perfect reality and fulfill Fromm's depiction of love as a practice

On your second point, philosophers have spent time thinking about different kinds of friendship and their value. It appears to many that friendship (ideally) involves reciprocal care stemming from a combination of what some philosophers call beneficent love and unitive love. The first involves desiring the good of the beloved and the second involves a desire to be with the beloved. Being friends with a stranger would seem to fall short of friendship unless there was reciprocal affection and a desire to get to know each other so that you both are no longer strangers. As for time and space and friendship, allow me to suggest that this depends on one's values and focus. If you develop a friendship with a co-worker but once you leave work for another job you two make ZERO effort to care for each other (and if the former co-worker contacted you, you would not reciprocate or even read their emails pleading for your attention because they are diagnosed with cancer) then I suggest this was a friendship of convenience. On the other hand, let's imagine the friendship is stronger: maybe you have fallen out of communication, and yet IF the co-worker were to reach out to you, you would respond with loving care, then I suggest the friendship is still there and has enduring (rather than temporary) value.

The version of Occam's Razor quoted above seems to support solipsism, the view that only one's conscious experience exists, over a view which also admits the reality of the external world. After all, solipsism is committed to fewer entities than the latter view, which also countenances the existence of stars, atoms, and rollercoasters.

I'll interpret the quote that explicates Occam's Razor as holding that the following is a priori: if we have two theories, X and Y, and Y says that fewer kinds of things exist than X does, then Y is more likely to be true, on some given some body of evidence, than X. This principle does indeed indicate that we should take solipsism to be more likely to be true than realism about the external world. The problem is that the principle isn't quite right.

As it stands, the above principle says that the theory on which nothing exists is more likely to be true than any other theory, given our current evidence. No matter what you take our current evidence to be, even if you restrict our evidence to conscious experience, the theory on which nothing exists is almost certainly false. For if there were nothing, there would be no conscious experience. So, given our evidence, the theory on which nothing exists is less likely to be true than either solipsism or realism about the external world, contradicting the above version of Occam's Razor.

This is why Occam's Razor often has a clause specifying that all other theoretical virtues, aside from ontological parsimony, must be equal in order for Y to be more likely than X. By "theoretical virtues" I just mean whatever features theories can have that increase their likelihood of being true, such as explanatory power. If we were to add such a clause to the version of Occam's Razor I formulated above, it should no longer be obvious whether it supports solipsism over realism about the external world. The reason is that if realism explains more of our evidence than solipsism or explains the evidence better, this new principle will say that realism may be more likely to be true despite its positing more kinds of entities.

I leave it up to you to determine whether realism about the external world in fact has more theoretical virtues like explanatory power than solipsism does.

As you've described the case, there's something the inventor could do that would save lives. There's also a dispute about how to analyze the notion of a cause. Some would say (your friend apparently is in this camp) that absences—in the case, not doing something—can't be causes. Others disagree and provide accounts that allow absences to be causal. This is an abstract and complicated issue, but how much difference will it make to how we judge the inventor?

Suppose I'm in a war zone and happen to know that there's an IED in a certain spot. I see someone running on a path that will take him over the IED and almost certainly leave him dead. Let's assume I even know who it is and know that in all relevant respects, he's an innocent. As it happens, I'm behind a barrier, but I could easily warn him. I don't. He runs over the IED and dies in the blast.

Is there something I could have done that would have saved him? We've already said yes. Would it have come at any significant cost? We can stipulate for purposes of this example that the answer is no. Should I have warned him? I'd say yes; I'd hope your friend would too. Was my silence a cause (note: I didn't say the cause) of his death? Why, exactly, does it matter beyond what we've already said?

Change the story a bit. Before he gets to the IED, the running man yells to me: "Is it safe ahead?" I lie and say yes. Was my lie a cause of his death? Maybe there's less dispute about that in this example. In any case, there's likely to be more agreement that the lie is even worse than saying nothing. But unless using the word "cause" is just a way of talking about culpability, it's not clear how much difference worrying about the fine points of causation makes.

We can imagine other variations. We might think that even though the lie would make me even more culpable, I'd still be less culpable than if I'd shot him. There are interesting and tricky questions here about responsibility. And for those whose tastes run to analytic metaphysics, there are interesting and tricky background questions about the best way to analyze causation. But my hunch is that in the case of the inventor and in the case of the IED, trying to sort out the metaphysics of causation is likely to be less useful than starting with what everyone can agree on and worrying about the question of responsibility in the morally weighted sense. In the case you and your friend are arguing about, everyone can agree that it's in the inventor's power to save lives. I'd hope we'd also agree that it's wrong of him not to. We can also agree that there are even worse things he could do—like helping to spread the disease among the very people he's chosen to keep the cure away from. But once we have all of these sorts of details on the table, it's not clear what's added by taking sides on whether or not to use the word "cause."

Great questions and concerns. For most philosophical theists (those who affirm the existence of God) "good" and "evil" need to be used with the same sense / meaning in terms of humans and God. For you to be compassionate and God to be compassionate and to be called 'good' presumably we mean praise-worthy / desirable / it is better that there is such compassion rather than not. But value judgements are often contextual depending on those involved. For those in the Abrahamic faiths (Judaism, Christianity, and Islam), God is understood to be the creator and sustainer of the cosmos, who is revealed in human history through prophets and (for Christians) in the incarnation. As such, God is not to be assessed as we would assess a human bi-stander. So, for you and I to not prevent a murder when we could do so is blameworthy. Does it follow that if God has created and sustained a cosmos in which there is murder, then God is blameworthy? Maybe, but so many factors enter into this. One has to do with what is called the Free Will Defense, and the appeal to Greater Goods. Check out the entry Philosophy of Religion on the free online Stanford Encyclopedia of Philosophy. Most theists believe that when something is evil (murder of innocent persons) this is contrary to the will and nature of God, a misuse of power, a destroying of something sacred. It is (as you might explore in the free will defense) never justified (right or ultimately good) from the standpoint of the Abrahamic faiths. Nonetheless, most philosophers in this tradition contend that an all good God may allow some evils in order to ultimately redeem both victims and victimizers. I have worked up such a view in two books you might check out: Contemporary Philosophical Theology co-authored with Chad Meister and What is Philosophy of Religion? Your concerns and questions are excellent and I hope you might find one of these sources helpful.

The reason you feel you don't understand the claim is because it's nonsense.

I know that there are three pillows on the bed behind me, but no science was committed in finding that out. I just turned around, looked and counted. I know that I had dinner with friends yesterday. No scienceing there either. I just remember. I know that one of our neighbors recently quit a committee he'd been a member of. Once again, no science; someone in a position to know told me. In fact, it's safe to say that by far most of what we know we know without anyone doing science.

Of course people doing science make observations, consult their memories and get information from other people. But so does everyone, and most of us are not scientists and don't do science. The fact that X has important things in common with Y doesn't make X a Y.