We are sure with 99%+ probability both were real people, it would be possible but really difficult to fake all the evidence of their existence.
We are sure with quite high but lesser probability that the broad strokes of their life are correct: Socrates was an influential philosopher who taught Plato and was sentenced to death, Muhammad was a guy from Mecca who founded Islam and migrated to Medina, then returned to Mecca with his followers.
We think some of the specific details written about them in history books might be true, but definitely not all of them. Muhammad might have lived in a cave during his young life, and Socrates might have refused to escape from his death sentence, etc.
Mohammed is solidly part of history.
Certainly not more solid than Newton
No, around the same level as Socrates.
We are sure with 99%+ probability both were real people, it would be possible but really difficult to fake all the evidence of their existence.
We are sure with quite high but lesser probability that the broad strokes of their life are correct: Socrates was an influential philosopher who taught Plato and was sentenced to death, Muhammad was a guy from Mecca who founded Islam and migrated to Medina, then returned to Mecca with his followers.
We think some of the specific details written about them in history books might be true, but definitely not all of them. Muhammad might have lived in a cave during his young life, and Socrates might have refused to escape from his death sentence, etc.