However, expression may sometimes be simulated in order to attain the associated emotion. If we act mad, we often get mad, and thus, as we see in the plays of animals and children, merely assumed expression may lead to the real emotion. This way of attaining emotion by purposely enacting its known expression, we may call impression as the reverse of the expression order. Men may work themselves up into a fury, as well as vigorously express an anger directly occasioned. Actors and public speakers often take advantage of this reaction of expression on emotion, and thereby not merely affect an emotion, but have a certain real emotion, which cannot ever be naïve. Thus Macready as Shylock used to prepare himself and get up “the proper state of white heat” by violently shaking a ladder. Poe in one of his tales makes a detective say, when wishing to know the thoughts of a wicked man, “I fashion the expression of my face as accurately as possible in accordance with the expression of his, and then wait to see what thoughts or sentiments arise in my mind or heart, as if to match or correspond with the expression.” This method of acting like another, that we may have and so know his thoughts and feelings, is a very difficult way of mind-reading. But expression is often simulated on one or both sides with full understanding of it as such. This enters into play, and is the essence of the dramatic art. That the word _play_ denotes both the sportive imitative actions of animals and men, and also a dramatic representation is not fortuitous or arbitrary. It is noticeable that among the lower animals the earliest and commonest play is playing at being angry or frightened, which corroborates the view of these emotions as probably the earliest and most fundamental in life. The correlated nature of fear and anger is shown by the way they are played at; thus you often see one dog with a show of anger chasing another who simulates fear, and then the parts are exchanged.