decline as compared with those commodities, in the production of which capital conspires less. It is already plain, that the class, Capital, is a smaller and a peculiar sub-class under the great class, Valuables; nothing can become Capital until it first become a Valuable, and then be _capitalized_ by a distinct act or intention on the part of the owner to reserve it in his own hands as an aid in further production, or transfer it to other hands to be so used, he meanwhile receiving profits as the reward of his abstinence; only a _transferable_ valuable, accordingly, can become Capital in any case, that is to say, it must be either a Commodity or a Credit, since personal services, though they may be sold, cannot be put over into the hands of another to be used in production, and therefore cannot become Capital in any case; and the chief peculiarity of this sub-class, Capital, is, unlike the three great classes of Valuables, each of which is utterly distinct from the other two, so that a Commodity can never become a Credit or a personal Service either of the others, that Capital as a class has extremely flexible limits, and consequently certain Commodities and Credits may easily enough be Capital to-day, and fall back to-morrow into their respective classes of mere Valuables and the next day come out from the class Non-Capital into the class Capital again. The same commodities and credits may be capital at one time, and non-capital at another, though they must be valuable all the time, or cease to be commodities and credits. When it is said that a young man's talents and skill are his "capital," the word of course is used in a metaphorical sense, and the meaning is, that skill and talents are _like_ capital in some respects. Popular language is not scientific.