Essentially,a theory is an abstract,symbolic representation
1个回答

essentially(副词做状语)

theory(主语)

is(系动词做谓语)

representation(表语)

an abstract symbolic(形容词做定语修饰representation)

楼上的回答有点问题,一个句子不可能没有谓语

of what is conceived to be reality (介词短语做定语修饰representation,of 后接的是介宾从句)