ON THE MODALS II: Metaphysical Modality I

In the last post, I concluded by saying modality divides majorly into two main aspects; modal metaphysics and modal epistemology. I also said I will begin with modal epistemology in this post and henceforth until we conclude all discussions on the matter before moving on to modal epistemology. But before I begin properly, let me anticipate modal epistemology by providing definitions of both aspects of modality. Modal metaphysics deals with the nature of modal operators (I hope you remember what modal operators are? They are ‘necessity’ and ‘possibility’). Modal metaphysics asks whether there are any characters to these operators. Modal epistemology on the other hand concerns itself with how these modal operators relate with us; whether we can have knowledge of these kinds. So over to the task at hand. Over to modal metaphysics.

Modal metaphysics holds that possibilities and necessities are comparable to space and time, in that they are not so much at our disposal as we are of them. You remember Saul Kripke right, I mentioned him in the last post! He was the first to notice this and he rightly said that something is necessary if and only if (refer to the dictionaries at the bottom of the page for definitions of technical terms that I could not avoid) it does not just obtain in our world but in all possible worlds. If you think he was crazy with his talk about possible worlds, open a new tab and Google up Hugh Everett. He was the physicist who in 1957 proposed that there are many parallel universes due to the wayward behavior of quantum physics, and that our universe is but one among these universes. I’m pretty sure you would rather take the physicist’s words for it than you would a philosopher. But compare what both Kripke and Everett said and ask yourself whether the differences you observe are enough to classify Kripke as crazy and Everett as not crazy. I’m also pretty certain you have seen and read about parallel universes in many sci-fi movies and novels respectively. Thus, retain the image of parallel universes in your head whenever you see possible worlds. For Kripke (1970), necessities are the “come what mays” in all possible worlds. Let us take the most readily and yet most controversial example: God. Using Kripke’s analysis, God is a necessary being if and only if he exists in all possible worlds. This sort of Kripkean definition really make necessity a rare thing. Very few entities are considered as necessities among philosophers. The two that are grudgingly accepted are mathematical truths and logical truths. Even so, some philosophers still think these two are not necessary entities. But I leave the matter open. Whether 2+2=4 obtains at every possible world, and whether it could be B and be not B at the same time, you decide.

Stemming from this, Kripke developed the ‘Rigid Designator’ theory. By rigid designator, Kripke meant that there are some terms in our world which pick out the same object in every possible world. Examples include names such as Mike, Tom, Portia, and what have you; and natural kinds such as water, rocks, gold, cloud, etc. According to him, there is no possible world in which someone who bears your name and that person is not you. To understand him better, consider the following analogy. In the recent episodes of Flash, Barry Hallen and his friends juggled between two earths; our earth and a parallel universe which was called earth2. However, Barry Hallen did not turn out to be Cisco Ramon in earth2, neither did Dr. Harrison Wells turn out to be Inspt. Joe West. In both earths, names were constant –the personality and life may however be different. Names are rigid designators. Water is always H₂0 in every possible world, so too is gold always with the atomic number 79. Rigid designators are not to be confused with necessities. Remember that there is a T&C: whenever someone with your name exist in any world, that person is you; whenever anything exists in any world and the thing is called water or gold, that thing is chemically and constitutively water or gold. In technical terms, similar things as rigid designators (which are most of things we are familiar with) are contingent, and when they exist in a possible world, they exist as possibilities not as necessities.

However, shortly after Kripke groundbreaking severance of metaphysical modalities from epistemic modalities, some philosophers began to take the usage of ‘possible worlds’ seriously. For Kripke, these worlds may not be worlds at all, they may be anything you want them to be. But for these philosophers, possible worlds are worlds; no more no less. According to these group of philosophers, possible worlds are worlds that are not actual but merely possible. In this way, our world, the world you and I inhabit, is called the actual world because the events in our world are actually occurring. Whereas, the events in possible worlds are not actually occurring. The sum of all possible worlds is called possibilia, and the sum of the actual world plus possibilia is called logical space. It is so called logical space because it accommodates all that we can think, imagine and conceive. Some philosophers are more comfortable with saying that logical space is a synonym for possibilia rather than saying logical space contains the actual world and all the possible worlds. But again, that is remotely important.

This group of philosophers who think that possible worlds should be taken seriously, divides majorly into camps; the realists and the abstractionists camps. The realists are those who think that possible worlds are exactly real and concrete like our world. The abstractionists on the other hand think that possible worlds are not like our world. For the abstractionists, possible worlds are abstract entities like numbers and laws; it is not as if the number 2 is somewhere where we can go see it or that laws are physical structures like buildings and all. The realists, led by David Lewis, came first but because it seems preposterous what they say about possible worlds, the abstractionists emerged to offer a similar position that would more welcomed than what the realists offer. Hence, I will begin in the next post with the realist and discuss what they have to say about possible worlds so that we can easily comprehend and understand the angle where the abstractionist is coming from. But before we conclude this post, let us dwell a bit on why talks about possible worlds have become mainstay in philosophy to the extent that it is beginning to creep into our everyday analysis.

When someone asks you what you mean when you say “I could have been a doctor” or “WWII could have ended differently so that the Germans won”; you simply repeat the same thing without offering a real explanation. This sort of explanation is called a circular explanation, where you offer an explanation using the same words used in what you are trying to explain. Fr example, a kid asks you to define ‘flying’ and you said “flying is when you fly”.  That is what we do when we are asked what we mean with our modal expressions. We simply say “what else do you want from me; I could have been a doctor or the Germans could have won WWII”. But that is not an explanation, is it?! However, with the possible world device, we can offer a non-circular explanation. For instance, you can say; “what I mean is that in some possible world, I am a doctor” or “in some possible world, the world history after WWII is different because the Germans won”. See! Better right?! You know it is better! However, your inquisitor may say, how do you know this. You will have an answer for him or her when we begin to discuss epistemic modalities. For now, let him or her and you be content with the knowledge that we can explain in non-circular language what we mean when we use modal expressions of possibility and necessity. See you next week as we begin talks about metaphysical modalities. Hope you have had an enriching reading. I do not have references for the curious minds this week; I do but I fear they will defeat the purpose of it all. They would sound too aloof for they are highly philosophical. So I guess the post is adequate enough for an introduction.