First, one can say that one can oneself do one thing and another; secondly, that this man cannot do a certain thing, but that man can; thirdly, that this man can do a certain thing and something else; fourthly, that neither can one do a certain thing oneself nor can any one else do it; fifthly, that one cannot do a certain thing oneself, but that some one else can; sixthly, that one can do something oneself, but the other person cannot do something else.