An idea is simply the intellectual representation of a thing. An idea may be clear or fuzzy, useful or useless, represent a real thing or a non-existent thing, but it cannot, strictly speaking, be true or false. It may be a good representation of a thing or a bad representation of a thing. The notion of true and false is applicable only to judgments . Judgments are expressed in propositions.
Propositions express the agreement or non-agreement between at least two ideas.
Therefore, only propositions may be properly said to be true or false. Arguments are made up of propositions. More about this in a moment. The meaning of truth and falsity is very important. This is probably the most common way in which we check to see whether or not a judgment is true.