In our reasonings concerning matter of fact, there are all imaginable degrees of assurance, from the highest certainty to the lowest species of moral evidence. A wise man, therefore, proportions his belief to the evidence.
Tell people there's an invisible man in the sky who created the universe, and the vast majority will believe you. Tell them the paint is wet, and they have to touch it to be sure.
Give me the storm and tempest of thought and action, rather than the dead calm of ignorance and faith! Banish me from Eden when you will; but first let me eat of the fruit of the tree of knowledge!