Although to penetrate into the intimate mysteries of nature and thence to learn the true causes of phenomena is not allowed to us, nevertheless it can happen that a certain fictive hypothesis may suffice for explaining many phenomena.

—Leonhard Euler

TOPICS: philosophy, nature, conjectures

It is the first duty of a hypothesis to be intelligible.

—Thomas Henry Huxley

TOPICS: research, conjectures

In mathematics the art of proposing a question must be held of higher value than solving it.

—Georg Cantor

TOPICS: problems, conjectures

SOURCE: A thesis defended at Cantor’s doctoral dissertation.