concern for Cassius's welfare
Cassius a ruthless manipulator. Caesar says of him, "Yond Cassius has a lean and hungry look; He thinks too much: such men are dangerous." (I. ii. 190-195)
Firstly, and mainly, he does it by persuasion. Have a look at Act 1, Scene 2 in Julius Caesar, and look at the speeches Cassius makes to Brutus: he makes arguments against Caesar, based on Caesar's ambition.
Cassius.
Cassius was not Caesar. Cassius wanted to kill Caesar for jealousy and some other issues.
HorseIsle Answer --> Julius Caesar
Cassius wants to kill Caesar
Cassius. He hath a lean and hungry look.
what weaknessess did cassius see in caesar
Cassius and Caesar, according to Shakespeare's play, were childhood friends (Cassius told a story of how he even saved Caesar from drowning in the Tiber River). Obviously, they were once good friends. However, Caesar gained more power and disregarded Cassius (Cassius also became more jealous and was not so friendly in return). Caesar had new friends, like Antony and Brutus, who were loyal to him. Caesar did not need Cassius to be his friend; he felt threatened by Cassius at one point. He said to Antony that he did not trust him (he was a thinker, probably plotting something devious). Caesar had hubris and did not feel threatened, really, by anyone. Obviously, Caesar undermined Cassius and did not care for him as a friend.
Cassius. "Yon Cassius has a lean and hungry look. He thinks too much. Such men are dangerous."
"Yond Cassius has a lean and hungry look. He thinks too much. Such men are dangerous."