"...no one has hitherto laid down the limits to the powers of the body, that is, no one has as yet been taught by experience what the body can accomplish solely by the laws of nature, in so far as she is regarded as extension. No one hitherto has gained such an accurate knowledge of the bodily mechanism, that he can explain all its functions... no one knows how or by what means the mind moves the body, nor how many various degrees of motion it can impart to the body, nor how quickly it can move it. Thus when men say that this or that physical action has its origin in the mind, which latter has dominion over the body, they are using words without meaning, or are confessing in specious phraseology that they are ignorant of the cause of the said action, and do not wonder at it. ...I ask such objectors, whether experience does not also teach, that if the body be inactive the mind is simultaneously unfitted for thinking? ...the mind is not at all times equally fit for thinking on a given subject, but as according as the body is more or less fitted for being stimulated by the image of this or that object, so also is the mind more or less fitted for contemplating the said object. ...I would further call attention to the mechanism of the human body, which far surpasses in complexity all that has been put together by human art... from nature, under whatever attribute she be considered, infinite results follow. ...I submit that the world would be much happier, if men were as fully able to keep silence as they are able to speak. Experience abundantly shows that men can govern anything more easily than their tongues, and restrain anything more easily than their appetites; whence it comes about that many believe, that we are only free in respect to objects which we moderately desire, for such can easily be controlled by the thought of something else frequently remembered, but that we are by no means free in respect to what we seek with violent emotion, for our desire cannot then be allayed with remembrance of anything else. However, unless such persons had proved by experience that we do many things which we afterwords repent of, and again that we often, when assailed by contrary emotions, see the better and follow the worse, there would be nothing to prevent their believing that we are free in all things. ...men believe that themselves to be free, simply because they are conscious of their actions, and unconscious of the causes whereby these actions are determined; and further, it is plain that the dictates of the mind are but another name for the appetites, and therefore vary according to the varying states of the body. Everyone shapes his actions according to his emotion, those who are assailed by conflicting emotions know not what they wish; those who are not attacked by any emotion are readily swayed this way or that. All these considerations show that a mental decision and a bodily appetite, or determined state, are simultaneous, or rather are one and the same thing, which we call decision, when it is regarded under and explained through the attribute of thought, and a conditioned state, when it is regarded under the attribute of extension, and deduced from the laws of motion and rest... we cannot act by the decision of the mind, unless we have a remembrance of having done so. ...Again, it is not within the free power of the mind to remember or forget a thing at will. ...the decisions of the mind arise in the mind by the same necessity, as the ideas of things actually existing. ...those who believe, that they speak or keep in silence or act in any way from the free decision of their mind, but do dream with their eyes open."