And besides, when such an error or illusion prevails, its hold upon the mind is confirmed and rendered almost invincible by the circumstance, that it is interwoven into the structure of all our language. In this case in particular, we never cease to speak of "the active principles," of "the ruling passion," of "ungovernable desire," of "the dominion of lust," of being "enslaved to a vicious propensity;"--in a thousand ways, the idea that there is a real efficiency in the desires and affections of the soul, is wrought into the structure of our language; and hence, there is no wonder that it has gained such an ascendency over our thoughts. It has met us at every turn; it has presented itself to us in a thousand shapes; it has become so familiar, that we have not even stopped to inquire into its true nature. Its dominion has become complete and secure, just because its truth has never been doubted. The illusion in question, if it be one, has derived an accession of strength from another source. It is a fact, that whenever we feel intensely, we do, as a general thing, act with a proportioned degree of energy; and _vice versa_. Hence, we naturally derive the impression, that the determinations of the will are produced by the strength of our feelings. If the passion or desire is languid, (since we must use a metaphor,) the action is in general feeble; and if it is intense, the act is _usually_ powerful and energetic. Hence, we are prone to conclude, that the mind is moved to act by the influence of passion or desire; and that the energy of the action corresponds with the strength of the motive, or moving principle. Though the principle in question has been so commonly received, I think we should be led to question it in consequence of the conclusions which have been deduced from it. If our desires, affections, &c., operate to influence the will, how can it be free in putting forth volitions? How does Mr. Locke meet this difficulty? Does he tell us, that it arises solely from our mistaking a metaphorical for a literal mode of expression? Far from it.