Most people assume logic on their side, using the term without any apparent awareness of what it means.
Used appropriately, logic can clarify and resolve issues. Deployed inappropriately, it can squash creativity and be perceived as hostility.
What it is
Logic is a method of evaluating arguments. An argument is a series of premises leading to a conclusion. The logic of an argument can be judged in 2 ways:
Valid or Invalid
- If the conclusion follows from the premises, the argument is valid.
- If the conclusion does not follow from the premises, the argument is invalid.
To determine whether an argument is valid or invalid assume that the premises are true. An argument with false premises may still be valid or invalid.
Sound or Unsound
- If the argument is valid and the premises are true, the argument is sound.
- If the argument is valid and one or more premises is false, the argument is unsound.
What it isn't
An argument may be either valid or invalid, and either sound or unsound. Without an argument to be examined, the terms logical or illogical do not apply. A simple statement of belief is not an argument, and cannot be either logical (valid and sound) or illogical (invalid or unsound).
