There are in the intelligence or reason, as united with the will in the constitution of the mind, necessary convictions of the true, the just, the right. There are in the sensitivity, as united in the same constitution, necessary affections of the agreeable and the disagreeable in reference to various objects. The will as the power which by its _nisus_ produces changes or phenomena, is conscious of ability to go in either of these directions, or in opposition to both. Now when it makes its _nisus_ or volition in reference to the true, the just, the good; should we attempt to explain this _nisus_ by saying that the true, the just, the good, affect the sensitivity agreeably, this would only amount to saying that the _nisus_ is made towards the true, not as the true, but only as the agreeable; and then we would introduce the law that the _nisus_ is always made in the direction of the agreeable. But then again we might seek to explain why the _nisus_ is always made in the direction of the agreeable. Is it of an antecedent necessity? Then we have an absolute and universal necessity. Is it because to go in the direction of the agreeable seems most rational? Then it follows that the _nisus_ is made towards the agreeable not as the agreeable, but only as the rational; and then we would introduce the law that the _nisus_ is always made in the direction of the rational. But then again we might seek to explain why this _nisus_ is always made in the direction of the rational. Is it of an antecedent necessity? Then here likewise we have an absolute and universal necessity. Is it because to go in the direction of the rational seems most agreeable? Then we are winding back in a circle to our first position. How shall we escape from these difficulties? Shall we adopt the psychology of Edwards, and make the will and the sensitivity one? Then as the volition is always the strongest affection of the agreeable, if the sensitivity be necessary, volitions are necessary, and we are plunged headlong again into an absolute and universal necessity. If the sensitivity be not necessary, then we have shown fully, above, that we have to account for its various determinations just as we are supposed to be called upon to account for the various determinations of the will when considered as a power distinct from the sensitivity:--we are met with the questions, why does the sensitivity represent this object as more agreeable than that object?--or the same object as agreeable at one time, and disagreeable at another? Or if these various determinations are resolved into an antecedent necessity comprehending them, then we go up to the antecedent cause in which this necessity resides, and question it in like manner.