Amarism is a political movement that started unofficially almost immediately after Phylacism became the main trend in politics. It was formed by several spiritualists who thought it would lead to the falling apart of society. Apart from that, a lot of spiritualists wanted to gain more power and instate a theological state based around their beliefs. Trying to appeal to the masses against a political theory that infringed upon personal liberty might've helped them become more powerful.
However, their rise to power never came to fruition, since the people were not yet ready to engage in any conflict after the Pact War. Thus, the spiritualists eventually decided to support the first Furyhold monarch as he rose to power himself. Their aim was to have him be replaced just before or after he took power, but they did not realise that by giving him a spiritual or heavenly mandate, they gave him a large amount of theoretical power in the eyes of the general populace that was formerly following the spiritualists. The spiritualists were out of power from that moment and Amarism never settled within the hearts of the citizens of Cortus.