God exists. (English)
Est Deus. (Latin)
Gött existiert. (German)
Dios existe. (Spanish)
These sentences all convey the same information and have the same content; they all express the same proposition.
1.2.1.2 Modal Propositions
Most propositions are about the way things were, are, or will be. For example, “Germany won the Men’s World Cup in 2014” is a true proposition about the way things were. But some propositions are about the way things could be, could not be, or must be. Logicians call these modal propositions. Consider the proposition “Germany could not have lost the Men’s World Cup in 2014.” It is quite different from the first proposition, and it seems to be false. (Germany only beat Argentina 1–0, and they did so in extra time.) Logicians define three modes a proposition can take: necessity, impossibility, and contingency. A necessary proposition has to be true; it is not possible that it be false. For example, “All triangles have three sides” is necessary (or necessarily true or a necessity). An impossible proposition has to be false; it is not possible that it be true. For example, “All squares have eleven sides” is impossible (or necessarily false or an impossibility). A contingent proposition is neither necessary nor impossible. A contingently true proposition might have been false, and a contingently false proposition might have been true. So, “Germany won the Men’s World Cup in 2014” is contingently true and “Argentina won the Men’s World Cup in 2014” is contingently false.
Many important religious questions concern the modal status of propositions. Consider this proposition about God and creation: “At the beginning of time, God created the universe.” Many theists (people who believe that God exists) believe that this proposition is true. But does being a theist require that you think that this proposition is necessarily true? Perhaps not.
Some theists say it is not necessarily true. They say that God was free not to create the universe at all. God might have done no creating, in which case reality would have consisted of God but nothing else. Other theists say it is necessarily true. Given God’s very nature as a good, loving being, God had to create a world with beings other than God – beings that are capable of loving and being loved by God. God would not be perfectly good if God did not create such a world and such beings.
Some theists say it is possible that God is responsible for the existence of the universe, but that the universe never came into existence at any particular point in time. Some say this because they think that it is possible that the universe is eternal and so is God: they are coeternal. Some say this because they think that time itself depends on the existence of the universe, so that it makes no sense to talk about times prior to or outside of the universe. Despite denying that the universe came into existence at a particular point in time, these theists also say that, if it were not for God, the universe would not exist. So, for them, “At the beginning of time, God created the universe” is not necessarily true, even though they do think that the universe is completely dependent on God.
Atheists (people who believe that God does not exist) of course think that “At the beginning of time, God created the universe” is false. They think that, somehow, the universe exists uncreated – either because it exists of its own nature or because it exists for no reason at all. But even some theists think it is possible that the universe exists for no reason at all. That is, they admit that it is possible that the universe exists without existing for any reason or because of any prior cause. They think that “At the beginning of time, God created the universe” is true, not because it is necessarily true, but merely because it is the best overall explanation of what science tells us about the universe.
We will return to many of these questions about God and creation later in this book. For now, just remember that questions about modality – questions concerning whether a proposition is necessary, is impossible, or is neither – are some of the most important questions in philosophy and in religion.
1.2.1.3 A Priori and A Posteriori Propositions
Another important distinction among propositions concerns the ways we are capable of coming to know them. What philosophers call a priori knowledge of a subject (treat a priori as all one word) is knowledge capable of being had about that subject independently of any experience with that subject. For example, you can know a priori that if you roll two six-sided dice, the probability of getting a seven is one in six. (Here is the proof. There are six ways the first die can come out and six ways the second die can come out. That means there are thirty-six possible combinations for the sum of the two dice. Of those thirty-six possibilities, six of them add up to the number seven: 1 + 6, 2 + 5, 3 + 4, 4 + 3, 5 + 2, and 6 + 1.) So, in order to know that the probability of getting a seven is one in six, you do not need to spend hours and hours rolling dice. No experience of playing board games or casino games is necessary. You can work out the answer in your head or on a sheet of paper. In other words, you c...