When John Adams states that men participate in society by "voluntary consent," he is endorsing the concept of the social contract, a political theory that argues that individuals enter into an agreement to form a society and submit to its laws in order to secure their rights and protect their well-being.
In his writings, Adams emphasizes the voluntary nature of this agreement, suggesting that individuals are not forced to join society but rather choose to do so for their own benefit. He argues that the purpose of government is to uphold the social contract.
So, Adams's emphasis on voluntary consent is significant because it distinguishes his approach from other social contract theories that emphasize coercion or necessity.