1) Some were pacifists who were against war in general.
2) Some were political objectors who did not consider the government of Germany to be their enemy
3) Some were religious objectors who believed that war and fighting was against their religion. Groups in this section were the Quakers and Jehovah Witnesses.
4) A combination of any of the above groups.
Some conscientious objectors did not want to fight but were keen to 'do their bit'. These people were willing to help in weapons factories and some went to the trenches to become stretcher bearers etc., though not to fight. Other C.O's refused to do anything that involved the war - these were known as 'absolutists'.
Lord Roberts wrote about conscription- "Compulsory service is, I believe, as distasteful to the nation as it is incompatible with the conditions of an Army like ours, which has such a large proportion of its units on Foreign Service. I hold moreover, that the man who voluntarily serves his country is more to be relied upon as a good fighting soldier than is he who is compelled to bear arms."
In 1916 the Military Service Act was introduced - this was soon nicknamed the "Batchelor's Bill" as to start with conscription only included unmarried men between 18 and 41. But it was widened in May 1916 to include married men as well. By April 1918, it had been expanded to include men up to 51.
However, the act also included a 'conscience clause' which allowed people the right to refuse to join up if it went against their beliefs. Those who claimed to be conscientious objectors…