ABSTRACT
One way of thinking about propositions is as the things that are true or false (what are called ‘truthbearers’). You might think it is only sentences which are true or false, but this can land you into trouble. For instance, it is eminently plausible to think that even if mankind had never existed, it would still be true that the world was round. However, if mankind does not exist then nobody ever says anything, and if nobody ever says anything then there are no sentences. So, the argument goes, if sentences are the truthbearers, then if none existed, nothing would be true or false. Allegedly, then, we need something mind-independent to be the truthbearers – and in step propositions. (Note that in this book we sometimes talk about sentences and sometimes propositions; usually there is no deep reason for this, and when there is, it should be obvious from the context.)
To use a metaphorical image, propositions are like sentences written down in God’s Big Book of Reality, wherein God has written down every possible statement and scribbled ‘true’ or ‘false’ next to it accordingly. Whether or not mankind existed, the proposition <the Earth is round> (that sentence in God’s Big Book that reads ‘The Earth is round’) would be true. Note that the symbols < and > around the sentence indicate that it is a proposition (as opposed to a sentence, which we surround with ‘ and ’).
