Virtue being, as we have seen, of two kinds, intellectual and moral, intellectual virtue is for the most part both produced and increased by instruction, and therefore requires experience and time; whereas moral or ethical virtue is the product of habit （ethos）, and has indeed derived its name, with a slight variation of form, from that word.It is probable that ἔθος, ‘habit’ and ἦθος, ‘character’ （whence ‘ethical,’ moral） are kindred words.