The Possibility of Necessity
Uploaded by palma on Oct 12, 2000
Sam Vaknin's Psychology, Philosophy, Economics and Foreign Affairs Web SitesSome things are logically possible (LP). Others are physically possible (PP) and yet others are Physically Actual (PA). The things that are logically necessary (LN) are excluded from this discussion because they constitute a meta-level: they result from the true theorems in the logical systems within which LP, PP and PA reside. In other words: the LN are about relationships between the three other categories. The interactions between the three categories (LP, PP, PA) yield the LN through the application of the rules (and theorems) of the logical system within which all four reside. We are, therefore, faced with six questions. The answers to three of them we know – the answers to the other three are a great mystery.
The questions are:
Is every LP also PP?
Is every LP also PA?
Is every PP also PA?
Is every PP also LP?
Is every PA also LP?
Is every PA also PP?
Every PP must be also LP. The physical world is ruled by the laws of nature which are organized in logical systems. The rules of nature are all LP and whatever obeys them must also be LP. Whatever is PA must be PP (otherwise it will not have actualized). Since every PP is also LP – every PA must also be LP. And, of course, nothing impossible can actually exist – so, every PA must also be PP.
That something exists implies that it must also be possible. But what is the relationship between necessity and existence? If something is necessary – does it mean that it must exist? It would seem so. And if something exists – does it mean that it was necessary? Not necessarily. It really depends on how one chooses to define necessity. A thought system can be constructed in which if something exists, it implies its necessity. An example: evolutionary adaptations. If an organism acquired some organ or trait – it exists because it was deemed necessary by evolution. And thought systems can be constructed in which if something is of necessity – it does not necessarily mean that it will exist. Consider human society.
There are six modes of possibility:
Logical (something is possible if its negation constitutes a contradiction, a logical impossibility).
Metaphysical (something is possible if it is consistent with metaphysical necessities)
Nomological (something is possible if it is...