It is reasonable to believe that Santa Claus exists.

It's more just completely ridiculous than funny, to be honest, but I suppose I'm not majoring in philosophy. The last bit was fairly funny :P But seriously, what sort of a course is philosophy at all? Like, will you actually be learning anything useful? Do you at anytime discuss what you would do if you walked into a room and there was fifty naked sexy women inside there? You might as well. But maybe I'm jumping the gun. That can't have been one of that fella's best ones, can it? Like, you can't really be expecting to prove that "Modal realism is true". "This is admittedly the most controversial of my starting premises." Maybe not... "I'll support it using three separate lines of reasoning." That part was kinda funny :) "First, it is a well known fact that the parameters of the physical constants of the universe must fall within extremely precise ranges in order to permit life. According to Stephen Hawking, if the relationship between the competing effects of explosive expansion and gravitational contraction during Plank time deviated in their ratio from unity by just one part in 10e60, the universe would have either re-collapsed in on itself or expanded too rapidly for stars to form.[3]" Beautiful. "One potential explanation for how the conditions of this incredibly slim possibility were met is the existence of other possible worlds. Although there is no reason to prefer this theory over others, it is at least plausible and can't be readily disproved." Yup... *cricket noises* How'd you support it there? "Second, modal realism is parsimonious. An extremely large, but finite set of alternate worlds could explain the existence of sentient life, however, as per the Principle of Sufficient Reason, the fact that some worlds exist but others don't would require an explanation. The hypothesis that all possible worlds are actual worlds is simpler." My goodness. Is this an example of what you're taking from your studies? I'm not even really sure what to say to that. Wouldn't it be even simpler to just say God did it? "Finally, it is reasonable to believe that modal realism is true irrespective of all other evidence." Why? "It is common in mathematics to postulate that abstract entities, such as sets, exist as real objects simply because they are useful constructs. Since there is no reason to doubt the existence of mathematical sets, they can be accepted uncritically for pragmatic reasons." Beautiful. But. They can be accepted as what? What's this got to do with anything? "The same is true of modal realism, which is useful for understanding possibility, probability, contingency, necessity, counterfactuals and other important concepts in epistemology, metaphysics, and philosophy of mind." First of all, is it necessary for understanding any of these concepts? Because if not, you've just gone and refuted yourself on your own nutty little point: "Second, modal realism is parsimonious." I just really don't know what to say to you :) Secondly, go get yourself into a proper course. You've plenty time to be dreaming when you're asleep. I just don't really understand why anyone would choose to study it, at least from what you've wrote, and of course if you were actually intending to make the most of your time in college. Is it to look smart in front of the ladies? Becuase if it's ladies you're looking for then I'd suggest persuing something a bit more lucrative. Maybe there's a lot of jobs to be got from a degree in philosophy though... I dunno? My argument: It's not reasonable to believe in something you don't have reason to believe in :P Thank you.