Man is a reasoning rather than a reasonable animal.

Of all these things respecting which learned men dispute there is none more important than clearly to understand that we are born for justice, and that right is founded not in opinion but in nature. There is indeed a true law (lex), right reason, agreeing with nature and diffused among all, unchanging, everlasting, which calls to duty by commanding, deters from wrong by forbidding... It is not allowable to alter this law nor to deviate from it. Nor can it be abrogated. Nor can we be released from this law either by the senate or by the people. Nor is any person required to explain or interpret it. Nor is it one law at Rome and another at Athens, one law today and another thereafter; but the same law, everlasting and unchangeable, will bind all nations and all times; and there will be one common Lord and Ruler of all, even God, the framer and proposer of this law.

Individual members are encouraged to independently strive to receive their own spiritual confirmation of the truthfulness of Church doctrine. Moreover, the Church exhorts all people to approach the gospel not only intellectually but with the intellect and the spirit, a process in which reason and faith work together.

Reason often makes mistakes, but conscience never does.

if a man asks you to go with him one mile, go two, and then you can say, 'You only asked me to go one mile, but I have gone two.' That is the counsel Jesus Christ gave. If you sit down and calmly reason the case, you cannot but discover that it gives you an influence over that man, which you could not gain by contending with him in anger. All the power which is gained by contending with people is usurped power

What an insidious thing is this culture amidst which we live. It permeates our environment, and we think we are being reasonable and logical when, all too often, we have been molded by the ethos, what the Germans call the zeitgeist, or the culture of our place and time.

Would you judge the lawfulness of pleasure, take this rule:
Whatever weakens your reason,
Whatever increases the authority of your body over your mind,
Whatever impairs the tenderness of your conscience,
Whatever takes away your relish for things spiritual,
Whatever obscures your sense of God,
That is sin to you, no matter how innocent it may seem in itself.

Though argument does not create conviction, lack of it destroys belief. What seems to be proved may not be embraced; but what no one shows the ability to defend is quickly abandoned. Rational argument does not create belief, but it maintains a climate in which belief may flourish.

Now, if you are in possession of a spirit or intellectuality of that kind, whereby you are enabled to read your own acts, do you not think that that being who has placed that spirit and that intelligence within you holds the keys of that intelligence, and can read it whenever he pleases? Is not that philosophical, reasonable and scriptural? I think it is....
Man sleeps the sleep of death but the spirit lives where the record of his deeds is kept—that does not die—man cannot kill it, there is no decay associated with it, and it still retains in all its vividness, the remembrance of that which transpired before the separation by death, of the body and the ever-living spirit.

When reason is adopted as the only—or even the principal—method of judging the gospel, the outcome is predetermined. One cannot find God or understand his doctrines and ordinances by closing the door on the means He has prescribed for receiving the truths of his gospel.