Honesty does not really exist. Any words spoken are immediately a lie as they are unable to convey the total complete and true nature of reality. Taken from another point of view, all information we receive comes through our senses. Our senses are faulty. The information is conveyed along neural pathways which depend upon the movement of sodium and potassium ions in order to trigger an action potential (neural electrical impulse). The neural impulses are modulated, filtered and amplified multiple times before they even reach the brain and so what the brain ultimately perceives is not True Reality. ie. the information received by our senses is faulty. As they say in the computer world--garbage in>garbage out. Where is the room for honesty? We can endeavor to be honest, but inevitably we fail. We are capable of being sincere, but not honest or true.
The sole exception to the above is the honesty given out by the mystics who through their own inner communion with the Lord, (ie. direct perception of reality without the lie of the senses and illusion) are able to pass on the truth to their disciples without even the need for the medium of speech.
The question is not, Can they reason? nor, Can they talk? but, Can they suffer? ~Jeremy Bentham