CHAPTER VI. 1. Of the two kinds of knowledge. 2. Truth and evidence necessary to knowledge. 3. Evidence defined. 4. Science defined. 5. Supposition defined. 6. Opinion defined. 7. Belief defined. 8. Conscience defined. 9. Belief, in some cases, no less from doubt than knowledge. [Sidenote: Of the two kinds of knowledge.] 1. There is a story somewhere, of one that pretends to have been miraculously cured of blindness, wherewith he was born, by St. Alban or other Saints, at the town of St. Alban’s; and that the Duke of Gloucester being there, to be satisfied of the truth of the miracle, asked the man, What colour is this? who, by answering, it was green, discovered himself, and was punished for a counterfeit: for though by his sight newly received he might distinguish between green, and red, and all other colours, as well as any that should interrogate him, yet he could not possibly know at first sight which of them was called green, or red, or by any other name. By this we may understand, there be _two kinds_ of knowledge, whereof the _one_ is nothing else but _sense_, or knowledge _original_, as I have said in the beginning of the second chapter, and _remembrance_ of the same; the _other_ is called _science_ or knowledge of the _truth of propositions_, and how things are called, and is derived from _understanding_. Both of these sorts are but _experience_; the former being the experience of the effects of things that work upon us from _without_; and the latter experience men have from the proper use of _names_ in language: and all experience being, as I have said, but remembrance, all knowledge is remembrance: and of the _former_, the register we keep in books, is called _history_; but the registers of the _latter_ are called the _sciences_. [Sidenote: Truth and evidence necessary to knowledge.] 2. There are _two things_ necessarily implied in this word _knowledge_; the one is _truth_, the other _evidence_; for what is not truth, can never be known. For, let a man say he knoweth a thing never so well, if the same shall afterwards appear false, he is driven to confession, that it was not knowledge, but opinion. Likewise, if the truth be not evident, though a man holdeth it, yet is his knowledge thereof no more than theirs who hold the contrary: for if truth were enough to make it knowledge, all truth were known; which is not so. [Sidenote: Evidence defined.]