Answer:
It means that making people say something they do not believe goes against their right to free expression.
Step-by-step explanation:
To sustain the compulsory [required] flag salute we are required to say that a Bill of Rights which guards the individual's right to speak his own mind, left it open to public authorities to compel [force] him to utter [say] what is not in his mind.
It means that making people say something they do not believe goes against their right to free expression.
although it was up to public authorities to convince him to say what is not his mind; he did not have to in any way, because he has rights-- they could try to convince him but anything that is 'force' could potentially be illegal actually:
the use of intimidation or threats to force (or prevent) someone to do something they have a legal right to do (or not to do). Charges typically are enhanced if physical force was used or threatened
In conclusion," B-It means that making people say something they do not believe goes against their right to free expression," because it not only goes against their right of free expression but threatens the authorities for intimidating threats when they have a legal right to not say what is not his mind.