A postulate is a theory or supposition. It can not be easily proved to be true. The expression, 'lend [one]self' means to be pertinent, relevant, or applicable to a specific purpose.

They are accepted as being true, so they do not need to be verified/proved. As a result they do not lend themselves to direct verification. Although they can be wrong, like the postulate made by Greek astronomer who postulated that the earth was at the center of the universe. And funny thing is some people believe postulates cannot be wrong. Here is a discussion you may find useful: https://www.quora.com/What-are-some-remarkable-postulates-which-turned-out-to-be-wrong