But perhaps it may be objected to me, that I have against my own rules introduced vices, and of a very black kind, into this work. To which I shall answer: first, that it is very difficult to pursue a series of human actions, and keep clear from them. Secondly, that the vices to be found here are rather the accidental consequences of some human frailty or foible, than causes habitually existing in the mind. Thirdly, that they are never set forth as the objects of ridicule, but detestation. Fourthly, that they are never the principal figure at that time on the scene: and lastly, they never produce the intended evil.