And that we are contented Caesar shall
Have all true rights and lawful ceremonies
It shall advantage more, than do us wrong (III.i)

Here, having just killed Caesar, Brutus insists that Antony speak at the funeral as a show of respect. In his mind, this is the ethical and morally correct stance. For Brutus, ethics and morals are tied closely with laws and tradition. Abiding by the laws of storied institutions implies moral rectitude, and Brutus believes that by displaying his proper adherence to what is lawfully correct, the public will reward him. But the public, as it turns out, is fickle and cares little for laws and ethics. In this way, Brutus’ rigid moral stance inhibits his ability to read the pulse of the Roman populace, and thereby limits his prowess as a politician.

It is a creature that I teach to fight,
To wind, to stop, to run directly on,
His corporal motion governed by my spirit (IV.i)

Here, Antony is speaking to Octavius about the third leader of their Triumvirate, Lepidus. Antony speaks rather dismissively of Lepidus’ decision-making skills and independence. Rather, in Antony’s mind he functions as a tool or loyal beast of burden that can be directed in whichever way he wishes. This contrasts rather drastically to Brutus’ strict adherence to rules and civility. Antony here is able to ruthlessly dehumanize others, and view them strictly in terms of their utility. What can Lepidus do for him? How can he be used to offer maximal advantage? The focus is on strategy. This is why Antony is a superior politician to Brutus, because he is willing to disregard morals in favor of gaining the upper hand.

Let me tell you Cassius, you yourself
Are much condemned to have an itching palm,
To sell and mart your offices for gold
To underservers (IV.iii)

Here, Brutus reprimands Cassius for allowing his troops to take bribes from the Sardians, where they are presently camped. Brutus has condemned a man named Lucius Pella because he has broken the law. Cassius has appealed to Brutus to forgive the man, because he knows him personally and because he is a valuable asset to their cause. However, Brutus will not hear of it. No matter how valuable Lucius Pella may be, he broke the law, and therefore must be punished. Once again, Brutus shows he is pedantically committed to the rule of law, even if it costs him a valuable strength. Although Brutus here wants to be lawfully consistent, he overlooks strategic investments and advantages and comes off as self-righteous to a fault.