Both the simple present and the simple past can refer to the present.What's the difference between the two?
The simple present is used to talk about what is generally true, which covers a present period of time without a definite beginning or end and has the implication that what is talked about holds good for all time. It is suitable for the general timeless statements or the expression of “so-called eternal truth”. The simple past with reference to the present usually expresses the speaker’s attitude or hypothesis. The attitudinal use normally occurs in independent clauses expressing a less direct question, request or suggestion and implying of politeness on the part of the speaker.
