Solipsism vs. Ockham

First, I’m what I believe is technically called a “philosophy noob.” I haven’t read nearly enough, and can’t follow half of what I read, since philosophers sometimes seem to me to speak a special language that one needs to learn in order to read about philosophy.

Second, I’m not a solipsist. I don’t find the argument at the end of the linked URL compelling, though; if it were to be true that I was imagining other people, I don’t see why I couldn’t imagine a language to communicate with those people and to express that I’m a solipsist. Again, though, I may be misunderstanding the argument. Anyway, the reason I’m not a solipsist is that it seems easier to assume that everyone else exists; life is pretty pointless if it’s all a dream, so I’ll assume reality exists and go from there.

Now on to the actual post:

Ockham’s razor tells me that “entities are not to be multiplied beyond necessity.” Another way to put it might be (correct me if I’m wrong) “if you can explain something using 5 entities, and all evidence points to 5 entities, there’s no reason to assume there’s a 6th”. Of course, once evidence for the 6th pops up, Sir William does not warn us against adding that 6th.

But I know I’ve had dreams with other people who seemed to have their own motivations. I don’t see a good reason to reject solipsism other than that it makes wondering about anything else rather pointless.

So, if I don’t use Ockham’s razor to cut down to the single entity (me), how can I use it at all? Doesn’t it mean that I might as well assume that everything that I can possibly think of must exist?

I know I must have some holes here. Please help me find them.

Same here. Assuming an external reality doesn’t take a lot of furrowing of the brow and it works just fine as a method of living.

It makes sense too, because I just can’t imagine that I would ever imagine a world in which George W. Bush would become President of The United States, or a world in which anyone would ever write “existence qua existence.”

I find it simpler to come to the conclusion that there is no rational decision between solipism and external reality, that there is no proof I myself exist, and that there is no evidence the universe was not created last thursday as it presently exists.

Therefore, it is simplest to behave as if there is an external reality, I exist, the persons around me exist, and the universe has the age as stated by our best scientists.

Assumption: I exist.

I receive sense data in the form of music, poetry, art, natural wonders, and the like that I know I am incapable of creating.

Either my mind is bifurcated, and there exists another me feeding me this sense data, or the universe exists.

Either possibility refutes soliptism.

That seems to me a wildly unsupportable assumption. Also circular.

I’m no solipsist, because solipsism (as I’ve always heard it defined) is an affirmative belief that I am alone in the universe. There’s no evidence for that. There’s also no particularly good evidence for the belief that I am not alone in the universe. Ergo, I am a skeptic – I’m quite convinced of my own existence (as something, not necessarily as a human) and I’m reasonably sure of logical truths (2+2=4, e.g.), but I doubt the existence of the world around me.

It’s not like that’s a big deal, though. Even if the world doesn’t really exist, my perception (imagined though it may be) is reasonably internally consistent, and I suffer – actually suffer – if I do things which would bring on my suffering in the world, whether it exists or is imaginary. Therefore, it’s good sense to assume that the world is largely how it appears when making decisions, even if there’s no good evidence for that proposition. Which there isn’t.


Let me put my question another way.

I see someone pick up a glass. I can:
A) Assume that the person picked up the glass on the orders of some invisible entity.
B) Assume that the person picked up the glass.
C) Assume that I imagined both the person and the glass.

I will pick B. Whether conciously or not, I’m using Ockham’s razor to cut down from me + glass + person + invisible entity to me + glass + person. Wouldn’t it be simpler to cut down to just me? Why can I use Ockham’s razor to go from A to B, but not B to C? I know I don’t use Ockham’s razor to go from B to C, so am I justified in using Ockham’s razor at all?

See, my point in my post is that I asked myself if there was a rational difference between A, B, and C.

A and B are the same, from my perspective, though. So, it’s either,
A: That person picked up the glass.
B: I am mistaken but I observed the person picked up the glass.
C: I imagined the person and the glass, but in my imagination, the person picked up the glass.

Of course, B and C aren’t that different, either. But neither are A and C. A and B are different.
So, there is no rational difference between A and C and B and C, from my perspective. Therefore, C can be, as a practical matter, discarded.
A and B can be differientated as far as confidence levels. If the person was far away, perhaps I am not as sure of A as I am of B. If the person is near and familiar, I am nigh positive that A is true, or someone is running a complicated deception. Thus, A.
But C can not be seperated from anything, and can always be mentioned as a possible option. It is unfalsifiable. And thus, as a practical matter, can be discarded.

It still may be true. But there’s no evidence of it.

If you really want to be a philosophy snob, then you need to know that there is really no such thing as Ockham’s Razor. The quote attributed to him, entia non sunt multiplicanda praeter necessitatem was manufactured by others. And what he did write, frustra fit per plura, quod potest fieri per pauciora (It is idle to do by many things what may be done by fewer), wasn’t even original to him. It was written a generation earlier in Petrus Aureolus, ‘The Eloquent Doctor’ (in 2 Sent. dist. 12, q. 1).

For me Ockham’s razor proves that solipsism is false.
For example, the simplest reason I am not currently fucking Angelina Jolie, after having just rolled off of Nicole Kidman and eyeing the Jessica Alba for the near future is that I don’t solely exist and that the universe is not a manifestation of my own imagination.


E-Sabbath, A and B are unfalsifiable too. You can never prove or disprove that’s what happened because your only measurement tools (i.e., your perceptions) are the very things you’re trying to prove the accuracy of. Ergo, Occam’s Razor doen’t cut either way – there’s no evidence for either A, B or C that does not depend on an a priori assumption that your perceptions are correct.


I’m not buying that fewer entities constitutes a simpler explanation in this case. The way I’ve often heard the Razor stated is “Don’t multiply entities beyond what is necessary to explain a given phenomenon.” If the phenomenon contains multiple entities, then an explanation containing multiple entities is precisely the right explanation for that phenomenon.


A. A dog has 4 legs.

B. A dog has one leg and a device that creates a holographic projection of 3 other legs.

In (B), there are only 2 entities, yet it is a less satisfactory explanation. This is because the phenomenon being described is 4 legs. To describe 4 legs, it is necessary to posit 4 legs. Positing fewer entities than the number observed does not simplify the explanation.

The real problem is that you’re mixing philosophy and science. IMO, philosophy is mainly mental masturbation. One does have to make certain assumptions in science, one being that there is an objective reality that can be perceived and measured by us. If you throw that out the window, then there’s no point in using Occam’s Razor anyway. I could be a head-in-a-jar, imagining all of reality, but that’s an unfalsifyable premise, and I don’t see the point of entertaining such an idea.

Then let’s get a little more basic: Cogito ergo sum. Because I think and percieve, I know that I exist; that’s a pretty good assumption.
I cannot separate myself from myself and therefore cannot judge the accuracy of my senses. My senses are real because I think and percieve and therefore I exist, so my senses must be correct and what I see and touch must be real.
How I interpret what I see and touch is a whole different thing. I guess what I’m suggesting is “It isn’t important what you’re looking at, it’s how you look at it.”
Does that make sense?

This is not correct. Are you fucking Angeline Jolie in your dreams?

Even though the world of our dreams is entirely in our heads and we are the only ones actually present, we don’t do as we please. For some reason, even in our dreams unpleasant things happen, and we don’t always win the lotto and date supermodels.

So the fact that you’re not dating supermodels in real life does not prove that this world is not all in your head.

That’s an interesting tidbit of history, and I for one am grateful for the lesson. However, much the same can be said of the Pythagorean Theorem, but we still find that a handy name for the concept it describes.

So I’d propose that “Ockham’s Razor” is a perfectly serviceable name for that concept as well — even for use by philosophy snobs — despite the fact that Mr. Ockham had little to do with inventing or publicizing it.

Woah. I just understood everything in a post by Liberal, I think. Perhaps the curtains have been lifted, and now I can understand philosophy qua philosophy. :slight_smile:

Anyhoo… wouldn’t the proper philosophy snob response to that be that clearly the essence of Ockham’s razor exists, regardless of the existance of such a statement by William of Ockham? Ockham’s razor exists whether it was formulated by William of Ockham or just now on this message board (and, of course, it’s existance appears to lie somewhere in between).

That’s actually not a bad argument, despite its humorous presentation… but I know the things I accept as my dreams have involved bad things happening to me before, and often involve non-perfect things happening to me. Who’s to say this thing I accept as reality isn’t working exactly the same way as my dreams, remaining devoid of Jolie-Kidman-Alba perfection while including Bush as President and Liberal saying things I often can’t parse without working really hard at it?

But aren’t you using Ockham’s razor to discard my A? Why is “I observed someone pick up a glass on the orders of an invisible entity” the same as “I observed someone pick up a glass” if we aren’t rejecting multiplication of entities? Let me try one more time:

I see someone pick up a glass. I can:
A) Assume the person picked up the glass on the orders of an invisible entitiy.
B) Assume the person picked up the glass of their own volition.
C) Assume I was mistaken, and something else happened, but whatever happened was still taking place in a reality external to me.
D) Assume I am imagining the whole thing.
E) Assume I’m imagining something else, and only think I’m imagining this event.

In my normal day-to-day life, I will choose B. I may not have a strong belief that the person was acting under their own volition, but I will assume it is the most likely scenario until presented with evidence to the contrary. I don’t entirely rule out A, C, D, and E, but to differing degrees I accept them as possibilities.

I’m pretty sure I’m ruling out A by Ockham’s razor, or my own internal application that can be summed up in a manner similar to Ockham’s razor. I don’t assume A because the invisible entitiy is unnecessary to explain what happened.

I rule out C because I have learned to trust my senses, but it still involves assuming an external reality. Of course, if I get evidence that I was wrong about B, I move to C.

So, now that I’ve thought it out a bit more, the thing that keeps me from accepting D or E is that I really use a slight modification of Ockham’s razor (or maybe Ockham’s razor + another rule):

  • Entities are not to be multiplied beyond necessity.
  • An external reality is necessary.

I adopt that second one, as has been discussed above, pretty much arbitrarily (or aesthetically); life is boring if it’s just me, so I’ll take an external reality. That’s what’s bugging me in this; I could just as easily say, “Life is boring if there are no invisible pink unicorns, so I’ll assume they exist, too.” (and I say that from inside the atheist camp to mock my own people, btw, before anyone gets mad at me for using the condescending tone of some atheists :slight_smile: )

So… how can I make things make sense to me again? :slight_smile:

Correct me if I’m wrong:

You’re asking if it is not the case that a consequent application of Occam’s Razor will inevitably lead one to adopt the perspective of a solipist – because, in the final analysis, the only “entity” one needs, in order to explain things, is the self.

The existence of other entities, outside of the self, is an assumption. Employing Occam, the question then arises, is it “necessary” to assume the existence of these external entities?

That’s a pretty abstract question, I suspect; one with little practical meaning, and rather difficult to answer as well. I’m guessing that one can be more or less “radical” in one’s use of Occam. If you favor a more radical interpretation, then there is probably some merit to your argument. If you favor a less radical interpretation – for example, if you view Occam’s Razor more as a sort of guideline, rather than an iron-clad rule for thought – then you would probably conclude that, all in all, it is necessary to assume an external world of “entities.”

In addition, in order to address robertligori’s objection, you are stuck creating a second entity: if you reject the external world, you must assume a “cut-off” portion of the mind. That’s an entity. You must therefore decide between the two, and when it comes to that, alas, Occam’s is no guide.

Does not compute. Yes, you can know the content of your senses, but that doesn’t seem to me to mean that you can know that the content of your senses corresponds in any important way to real-world phenomena.


Oops, I posted my last reply without preview, so I missed this great reply:

Good point. I think I’d restate my understanding of the version of Occam’s razor that I use thus, then:

  • Assumptions are not to be multiplied beyond necessity.

The 1-leg-plus-holo-projector involves assumptions for which I have no evidence (I guess that’s why they’re called assumptions). I’ll try to get back to this thought below.

Yup, that sums up what I’m fumbling to ask. I think I’m a sort of a radical razorist (reductionist? I don’t know if that’s what the term means in philosophy; like I said, I’m a noob). I can’t think of any case where Occam’s razor fails in my understanding of reality; the explanation with the fewest assumptions is what I adopt until evidence convinces me that I need a new assumption (or, rather, until what I had taken as an assumption is “proven” to me). If I gain evidence that the invisible entity was influencing my glass-taker, I will switch to A in my list above.

But for some reason I don’t continue to solipsism. Everything could be explained by assuming the world is a dream taking place in my conciousness, whatever that conciousness might be. I feel strongly that “resistance is necessary” isn’t an assumption, but I’m having trouble backing it up.

I know that when I dream, characters do things that I do not personally will them to do. I accept that a part of me is doing that without my conscious knowledge. Why can’t the same part of me that controls all of those things in my dreams be controlling all of those things in reality? Note that what I’d be choosing between would be my conscious mind + my subconscious mind vs. conscious mind + my subconscious mind + reality, since my subconscious exists when I dream in the world that I accept as real. I don’t have to add that controlling part of my brain to replace reality; it’s already there in the reality version.

Whether or not the principle known as Ockham’s Razor was actually set forth by William of Ockham (and he did write Pluralitas non est ponenda sine necessitate, which translates literally into English as “Plurality should not be posited without necessity” according to several sources), it is an extremely useful principle (if not an inviolate law, of course).

In the case of solipsism, one must ask whether the self is the only explanatory entity necessary. I, for one, consider that a plurality of other entities is necessary in order to explain what my senses tell me, such as that the universe existed for 13.7 billion years before my senses did.