I often hear people ask questions formulated as “Is a thing possible?” such as, “Is hitting a baseball 500 feet possible?” Another form of this question would be, “Is it possible to hit a baseball 500 feet?” It is the same question and follows a modified form of “Is a thing possible?”
I assert that one does not gain any new knowledge of the subject of the question by asking this question, and one therefore ought not ask any question that takes the form of “Is a thing possible?” A careful and thoughtful assessment of the meaning of the word “thing” reveals that when one says “thing” one means, often among other things “that which is possible.” In the baseball question above, I think everyone would agree that hitting a baseball 500 feet is, in fact, possible, while those who are familiar with the sport will no doubt point out that there is little or no evidence that anyone has ever hit a baseball that far before. Being extremely difficult is not the same as being impossible, and not all possibilities are realities in our universe. Implicit in the definition of “thing” is the idea of possibility, and I would go so far as to state that the definition of the word “thing” is, in fact, “that which is logically possible.” Impossibilities, such as square circles or married bachelors, are simply not things! Take a second and think about whether your impression about things leads you to believe that a square circle is a thing. My impression of things doesn't lead me to believe that square circles are things.
Under that definition, when one asks the questions “Is a thing possible?” what is really being asked is “Is a thing a thing?” The identity property tells us that this statement is necessarily true. All things, according to the identity property, are things. By assuming that the subject of the question is a thing, one is assuming it is possible. No new information is gained by asking the question.
What I think people generally mean when they ask the question, and what I think is generally understood by the question is “Is a thing reasonable?” Using that formation, the question posed at the top becomes “Is hitting a baseball 500 feet reasonable?” To that I think we can safely say no. What about that which is impossible, such as our square circle? We can call those “not things.” So we have set “things” which includes all which is possible, and we have “not things” which includes all which is not possible.
One weakness of this line of thinking is the assumption I made at the beginning that all statements asking about the possibility of a proposition are necessarily statements about things, rather than not things. It is possible (or should I say reasonable?) to ask “Is not a thing possible?” but I would argue that not things are typically self-evidently not possible, and that people therefore don't tend to ask about their possibility.
The word nothing is generally assumed to be the antonym of the word thing, but in fact, it is not. It is categorically different. This can be shown by trying to put “nothing” into the category of “things” or “not things.” Nothing isn't a thing (it has NO THING right in the name), but is also consistent to say that nothing is not impossible, and is therefore not a “not a thing.” The definition of nothing is:
“That which has no attributes.”
One could claim that having no attributes is in fact an attribute, and that the definition therefore is absurd. To that, I respond that it is possible to express the definition of nothing as:
“That which has one and only one attribute: that it has no other attributes”
and arrive at the same meaning as the first, more simple definition. I will use the first definition for the rest of this argument. Any thought which can be expressed by naming attributes falls squarely into the category of possible or impossible, thing or not a thing. Whether we are sure which category it falls into or not is a different question. Nothing, though, does not have attributes which can be used to put it into either category. There is a difference between the word nothing and the concept of nothing. The word nothing has attributes; it is seven letters long, it sounds a certain way, it looks a certain way, etc..., but the concept for which it stands does not have attributes, and therefore cannot be said to exist (because existence is an attribute) or to not exist (because non-existence is an attribute). I suppose one could argue that non-existence is simply the lack of existence and is therefore not an attribute, and I guess that might be the case, but if not, then nothing is neither impossible nor possible.
Unless one can show that lack of attributes is an attribute (such as the attribute of not existing), one must accept that nothing is neither a thing nor not a thing.
I don't really know if all this is helpful, except that maybe it will help people to stop saying “is it possible...?” and help them to start saying “is it reasonable...?”
This whole thing is confusing and muddled, but whatever.