Which of these lines from the play indicates that brutus fears caesar will become a corrupt ruler?

"it must be by his death, and for my part/i know no personal cause to spurn at him"

"and, to speak truth of caesar/i have not known when his affections swayed/more than his reason."

"but 'tis a common proof/that lowliness is young ambition's ladder,"

"crown him that,/and then i grant we put a sting in him/that at his will he may do danger with."

brutus
it must be by his death, and for my part
i know no personal cause to spurn at him
but for the general. he would be crowned.
how that might change his nature, there's the question.
it is the bright day that brings forth the adder
and that craves wary walking. crown him that,
and then i grant we put a sting in him
that at his will he may do danger with.
th' abuse of greatness is when it disjoins
remorse from power. and, to speak truth of caesar,
i have not known when his affections swayed
more than his reason. but 'tis a common proof
that lowliness is young ambition's ladder,
whereto the climber upward turns his face.
but when he once attains the upmost round,
he then unto the ladder turns his back,
looks in the clouds, scorning the base degrees
by which he did ascend. so caesar may.
then, lest he may, prevent. and since the quarrel
will bear no color for the thing he is,
fashion it thus: that what he is, augmented,
would run to these and these extremities.
and therefore think him as a serpent's egg-
which, hatched, would as his kind grow mischievous-
and kill him in the shell.