Spring 2004
Phl 204
Statements
All of us are taught that there are grammatically correct ways of structuring sentences. In creative writing, we are asked to vary the style of our sentences to keep the interest of the reader. Philosophy is concerned with meaning. This means that the same thought can be expressed in a variety of ways. Consider these example sentences:
1. Only thinkers are philosophers.
2. If someone is a philosopher then that person is a thinker.
3. People who do not think cannot be philosophers.
Though in different forms, each of these expressed the same statement: “All philosophers are thinkers.”
Here are several kinds of statements:
Analytic statements are true because of the meanings of their terms and their logical form: “All single people are unmarried.” These statements of logical truth are sometimes called tautologies. “If I were born before the Battle of Hastings, I would be more than 900 years old.” These statements are logically necessary. “No amoebas are reptiles.”
Self-contradictory statements assert something that is logically impossible. “Fred walked away from the building without ever leaving the structure.”
Something can be logically possible if it can be described without self-contradiction. A villain in a story might destroy the world by the snapping of his fingers. This is contrasted with something that is logically impossible, like a three-sided square. In any possible universe, this would be false by definition. Statements can be true in a logical sense but untrue in other ways.
Something is scientifically possible if it is consistent with known facts
about the real world. “She can run a
mile in just under four minutes.” An
inconsistent statement would be “She can run across the
Something is practically possible if it is within human ability. For example, fish can breathe under water without a special apparatus, but people cannot. It is scientifically possible for animals to live under water, but not practically possible for humans. People could live under water, only if they have the right breathing equipment. In other words, conditions can be imaged which would allow for the logically possible to be practically possible.
Consider this: what is beyond logical possibility is also beyond scientific and practical possibility. What is practically possible is also scientifically and logically possible.
A basic principle of thought and logic is that a statement is either true or false, not both, and not neither. Some sentences have meanings which violate this rule.
False presuppositions violate the principle that a statement must be true or false. Someone asks you whether you have spent the $1,000,000 you got for your birthday. The answer is logically either “yes” or “no”, but if you did not get $1,000,000 for your birthday both answers are false.
Category mistakes link things that belong to mutually exclusive groups. If someone spoke to you of a particularly “sympathetic rock” they are probably telling you a joke or using a metaphor. Less easy to detect is something like the question “What lies beyond space?” “Beyond” is a special category that implies an “outside”. “Space” doesn’t have an “outside”.
Untestable principles are both tempting
and confusing. If it is logically or
scientifically impossible to get evidence for a statement then it is a set of
empty words. “Last night while you
slept, everything in the universe doubled in size!”