Final answer:
James Otis, a lawyer and statesman, condemned the writs of assistance and believed acts by Parliament infringing colonist's rights were invalid. His viewpoints contributed to the push for independence and self-governance, leading to the Declaration of American Rights.
Step-by-step explanation:
The individual who condemned the writs of assistance and stated that acts passed by Parliament against the rights of the colonists were invalid was Massachusetts lawyer and statesman James Otis. He passionately argued that the writs of assistance, which were general search warrants, violated the fundamental rights of the colonists.
His speeches and legal challenges galvanized public opinion and contributed to the American colonists' demand for independence. Furthermore, the philosophy of self-governance and the belief that laws interfering with colonial autonomy were unjust flourished among leaders such as Samuel Adams and John Adams. The widespread discontent culminated in actions like the drafting of the Declaration of American Rights during the First Continental Congress, stating that the colonies had never ceded to any foreign power the right to dispose of their liberties without their consent.