As soon as we realise it to be but this, its effect must cease instantly.  The power of conscience resides not in what we hear it to be, but in what we believe it to be.  A housemaid may be deterred from going to meet her lover in the garden, because a howling ghost is believed to haunt the laurels; but she will go to him fast enough when she discovers that the sounds that alarmed her were not a soul in torture, but the cat in love.  The case of conscience is exactly analogous to this.

And now let us turn again to the case in question.  Men of such a character as I have been just describing may find conscience quite equal to giving a glow, by its approval, to their virtuous wishes; but they will find it quite unequal to sustaining them against their vicious ones; and the more vigorous the intellect of the man, the more feeble will be the power of conscience.  When a man is very strongly tempted to do a thing which he believes to be wrong, it is almost inevitable that he will test to the utmost the reasons of this belief; or if he does not do this before he yields to the temptation, yet if he does happen to yield to it, he will certainly do so after.  Thus, unless we suppose human nature to be completely changed, and all our powers of observation completely misleading, the inward condition of the class in question is this.  However calm the outer surface of their lives may seem, under the surface there is a continual discord; and also, though they alone may perceive it, a continued decadence.  In various degrees they all yield to temptation; all men in the vigour of their manhood do; and conscience still fills them with its old monitions and reproaches.  But it cannot enforce obedience.  They feel it to be the truth, but at the same time they know it to be a lie; and though they long to be coerced by it, they find it cannot coerce them.  Reason, which was once its minister, is now the tribune of their passions, and forbids them, in times of passion, to submit to it.  They are not suffered to forget that it is not what it says it is, that

    It never came from on high,
      And never rose from below: 

and they cannot help chiding themselves with the irrepressible self-reproach,

    Am I to be overawed
      By what I cannot but know,
    Is a juggle born of the brain?

Thus their conscience, though not stifled, is dethroned; it is become a fugitive Pretender; and that part of them that would desire its restoration is set down as an intellectual malignant, powerless indeed to restore its sovereign.

    Invalidasque tibi tendens, heu non tua, palmas.

Conscience, in short, as soon as its power is needed, is like their own selves dethroned within themselves, wringing its hands over a rebellion it is powerless to suppress.  And then, when the storm is over, when the passions again subside, and their lives once more return to their wonted channels, it can only come back humbly and dejected, and give them in a timid voice a faint, dishonoured blessing.