Shakspere's teaching is, that if the nobler-gifted man who stands at
the head of the commonwealth, allows himself to be driven about by every
wind of the occasion, instead of furthering his better aims with all
his strength and energy of will, the wicked, on their part, will all
the more easily carry out their own ends. He therefore makes the King
say: [66]--

That we would do,
We should do when we would; for this 'would' changes...

Shakspere's friends understood the allusion contained in the first act,
after the apparition of the Ghost, when Hamlet calls for his 'tablets.'
They knew that the much-scribbling Montaigne was meant, who, as he
avows, had so bad a memory that he could not receive any commission
without writing it down in his 'tablets' (_tablettes_). This defect of
his, Montaigne mentions over and over again, and may have been the
cause of his many most ludicrous contradictions. [67]

After Hamlet has written down the important fact that 'one may smile,
and smile, and be a villain--at least, I am sure it may be so in
Denmark,' he exclaims:--'Now to my word!' That 'word' undoubtedly
consists of the admonition addressed to him by the Ghost, that Hamlet,
after having heard his duty, also should fulfil it--that is:--

'So art thou to revenge, when thou shalt hear.'

But he only recollects the last words of the Ghost; and Hamlet's parole,
therefore, is only this:--