Since, then, all passionate excitement is forbidden us, we are debarred from every kind of spectacle, and especially from the circus, where such excitement presides as in its proper element. See the people coming to it already under strong emotion, already tumultuous, already passion-blind, already agitated about their bets. The prætor is too slow for them: their eyes are ever rolling as though along with the lots in his urn; then they hang all eager on the signal; there is the united shout of a common madness.
Observe how “out of themselves” they are by their foolish speeches. “He has thrown it!” they exclaim; and they announce each one to his neighbour what all have seen. I have clearest evidence of their blindness; they do not see what is really thrown. They think it a “signal cloth,” but it is the likeness of the devil cast headlong from on high. And the result accordingly is, that they fly into rages, and passions, and discords, and all that they who are consecrated to peace ought never to indulge in.
Then there are curses and reproaches, with no cause of hatred; there are cries of applause, with nothing to merit them. What are the partakers in all this— not their own masters— to obtain of it for themselves? Unless, it may be, that which makes them not their own: they are saddened by another's sorrow, they are gladdened by another's joy. Whatever they desire on the one hand, or detest on the other, is entirely foreign to themselves. So love with them is a useless thing, and hatred is unjust.
Or is a causeless love perhaps more legitimate than a causeless hatred? God certainly forbids us to hate even with a reason for our hating; for He commands us to love our enemies. God forbids us to curse, though there be some ground for doing so, in commanding that those who curse us we are to bless. But what is more merciless than the circus, where people do not spare even their rulers and fellow citizens? If any of its madnesses are becoming elsewhere in the saints of God, they will be seemly in the circus too; but if they are nowhere right, so neither are they there.
Source: De Spectaculis (The Shows) (New Advent)