Joe Lau

Some basic terminology

Please make sure you understand how these terms are used:

  1. Quotation marks are used to talk about expressions in a language: "a" is the first letter of the alphabet. "Joe Lau" is a name.
  2. "Joe Lau" is a name but Joe Lau is a person and not a name. You can find "Paris" in "Paris is a beautiful city", but you cannot find the beautiful city of Paris in "Paris".
  3. "Joe" is one word but "Joe Lau" contains two words. A term has more than one word and can include names, descriptions, phrases, etc.
  4. We can talk about word types and word tokens. On this page you can only find one name (type) of a French city but many tokens of that one name. Here is another token of the same name type: Paris.
  5. A grammatical sentence usually has a meaning, but the meaning is not the sentence: "Paris is beautiful" is a sentence in English. It is different from the French sentence "Paris est belle", but they have the same meaning.
  6. Numerals are names of numbers. The Roman numeral "II" and the Arabic numeral "2" refer to the same number, i.e. 2.
  7. Many people also talk about the concept associated with an expression. A distinction is often made between the expression, the meaning of the expression, and the concept associated with the expression.
  8. A statement might be taken as a sentence that can be true or false. "Are you happy?" is a question and not a statement. "You are happy" is a statement.
  9. A belief is a state of mind and not a sentence. But we can express our beliefs when we utter a sentence sincerely. If Peter says "I am happy" sincerely, then Peter is expressing the belief that he is happy. The content of his belief is that he is happy.
  10. An argument is composed of more than one sentence. It is made up of premises and a conclusion. Here is an argument with two premises and a conclusion: The Sun is a hot place. Hot places do not have snow. Therefore there is no snow on the Sun.
  11. An argument is valid or invalid, depending on whether the conclusion follows from the premises. Never describe an argument as true or false.
  12. A sentence has a truth value. If the sentence is true, the the sentence is often labelled as T (truth). Otherwise F (false).