base on

base something (up)on someone or something

to ground something, such as one's opinion, decision, or thinking, on someone or something; to found one's ideas or attitude on something. (Upon is more formal and less commonly used than on.) I base my opinion on many, many facts. I based my opinion upon my own seasoned judgment.
See also: base, on

base on

v.
To form, develop, or found something on the basis of something else: I based my decision on the information you gave me. The film was based on a popular book.
See also: base, on
References in classic literature ?
And he sprang from the rock in order to inspect the base on which it had formerly stood.