Friday, 19 December, 1828
I have observed a slight disposition to deviate from those determinations of yesterday, scarcely twenty-four hours since the ideas were under examination. How unstable we are to ourselves, and promises made by imagination and to which no one is knowing but ourselves. I have frequently been astonished at myself that I would so frequently suffer these notions so frequently to deceive. But I am not alone in this situation, and it teaches this: that if you wish to have a man adhere to his promises, you have always a good witness to hear or his own hand with a pen to declare his assent. You will find this to be the case in many instances if you neglect to get good testimony.