Candid
Definition:
1) Free from prejudice; impartial.
2) Characterized by openness and sincerity of expression; unreservedly straightforward
Synonyms:
equal,equitable, fair, forthright, frank, free, geuine, guileless, impartial, objective, sincere, straightforward, truthful, unbiased, unprejudiced, unpretended, up front, upright
Passage:
    "Of all questions we ask about our world, none is more profound than 'Does God exist?' Every generation asks this question anew and answers it in its own way. Every generation has its own attitudes and its own relationship with the concept of a divinity. But one truth is constant: Wherever human beings have made history, they have talked about or written about God. Rare indeed is the mythology that does not contain some story of creation, of the origin of evil, and of an ultimate power ruling the universe and directing the destiny. "

                          -
The Existence of God (Essay), Readings for Writers p.438
Explanation:
     This passage obviously tackles a very controversial question which is "Does God exist?" However, the author does not answer the question but uses actual facts to exhibit to the audience what many other people  have done in the past when the question of God arises. This is evident in "But one truth is constant: Wherever human beings have made history, they have talked about or written about God." by using the "but" he shifts the readers attention from the topic if God exists to the topic of what people have actually done in refering to God. Therefore, he gives facts about subjects retaining to God, and at the same time avoids using his own theory to answer the question of God. The fact that he used a rhetorical question, "Does God exist" it suggests that we he will write will allow the reader to answer the question themselves rather for them. Therefore, because he does not give his own opinion about god, he is very straightforward in his facts and has no bias or lineancy to one side. The tone is characterized in a candid fashion.