Final answer:
The clause "That we invite Mr. Enders to speak" is a noun clause, serving as the subject in the given sentence.
Step-by-step explanation:
The clause in quotes "That we invite Mr. Enders to speak" is a noun clause. A noun clause functions as a noun in a sentence, which means it can act as a subject, object, or complement within the sentence. In the example provided, the noun clause acts as the subject of the sentence, stating the consensus reached by the group.
Unlike adjective clauses, which describe nouns, or adverb clauses, which modify verbs, adjectives, and other adverbs, noun clauses can take on the role of nouns themselves.