Policing Twitter will ruin its magic, internet entrepreneur Jason Calacanis told CNBC on Thursday.

"If they try to reverse engineer Twitter into being like Facebook, where you can't just put yourself on somebody else's wall — you can't go onto a journalist or a celebrity's or an author's page and challenge them — well that kills the whole reason for Twitter to exist," Calacanis said on "Squawk Alley."

"The entire magic of Twitter is that anybody can mix it up with anybody," he added.

Twitter CEO Jack Dorsey appeared on NBC Nightly News on Wednesday to discuss his decision to suspend InfoWars' Alex Jones for a tweet that linked to content encouraging violence, which violated Twitter's policies. Twitter suspended Jones on Tuesday for seven days in a reversal of its previous position, allowing the conspiracy theorist on its platform because he hadn't broken its rules. Twitter was one of the last major platforms not to remove Jones from its platforms.

"Whether it works within this case to change some of those behaviors and change some of those actions, I don't know," Dorsey said during the interview. "But this is consistent with how we enforce."

Calacanis, an angel investor and founder of Weblogs, said censorship and policing defies the whole point of Twitter, which is to encourage an "full contact debate" on an equal playing field.

Dorsey "wants to pretend that they're going to make it a civil place. Twitter is not designed to be civil," Calacanis said.

"If the president posts something, I can reply and put my message right underneath his. And if I want to call the president an idiot and he wants to call Omarosa a dog, that is why Twitter exists, for that kind of full contact debate," he added.

But Walter Isaacson, former CNN chairman and Time managing editor, said it's about time social media executives stepped in to moderate the online conversation.

"People like Jack Dorsey are going to say, 'Do I really want to be somebody who messes up democracy, messes up our civil society, or do I want to try to contain this platform?'" Isaacson said Thursday on CNBC's "Squawk on the Street."

Isaacson said Dorsey is stuck between the demands of his conscience and the demands of Wall Street, which incentivizes "ever growing numbers of users."

Twitter is "filled with bots, it's filled with trolls and it's filled with the type of people that if you were to have a responsible platform, you'd get rid of," said Isaacson, a professor at Tulane University.

"Companies probably should have a conscience, and if not they can be shamed or pushed into it. We are now in a world in which only the bottom line for investors seems to be driving things. But I think we can push back a bit on that," he added.

Isaacson and Calacanis did not agree on much, but both admitted Twitter would be better off without purely anonymous accounts.

"There's one thing they could do maybe to stop some of this, which is get rid of anonymous accounts," Calacanis said.