Toohey made his own goal, power over the opinions of others."
If an individual or a group does not want to allow you, your own opinions, they don't believe in individual rights. They are a collective, clan, gang, or mob that wants to control, manipulate, coerce, force their opinions on you.
This comes in many forms. Whether it by family, religion, culture, or just a group of people that want to tell you they know better than you, and your mind, nor opinion matters. These individuals don't believe in individual rights.
No matter if they are right about the facts regarding something, if you chose to disagree, that is your choice. Whether you do so, by your own evidence, or not. Even if you are wrong and they are right, in America you can chose to disagree.
But power lust like Toohey's was about being wrong and forcing that wrong opinion, ideas, facts, upon others, without the other individuals being able to agree or disagree. It was obey, or else, some retribution is heading for you.