I shall only add another observation to the ideas on which I have just dwelt: perhaps we should never have thought of applying the words which express action and motion, to all the operations of our souls, if we had not at first divided our spiritual being into a great number of dependencies, such as attention, reflection, thought, judgment, imagination, memory, and foresight; and if afterwards, in order to render intelligible the variable relations of these abstract parts of our mind (these parts of a unit which we have taken to pieces, though it composed that single being ourself) we had not been obliged to have recourse to some plain expressions, like those of action, motion, attraction, and repulsion; but this familiar use of these expressions, in order to explain the accidents of our intellectual system, very much resembles the use which we make of X in Algebra, to express unknown terms. In short, were we to submit the action of our souls to the laws of a particular movement, forming one of the dependencies of the great one, we should still have to explain the cause of the consciousness that we have of this action, which Atheists refuse to nature itself, at the very moment they make it the God of the Universe. Were reasoning able to subject all the operations of our mind to the impressions of external objects, we could not rank under the same laws, that consciousness which we have of our existence, and of the different faculties of the soul. This consciousness is not an effect, or the production of any known force, since it has been always in us independent of any external object, consequently we cannot investigate it. The conception of the existence of our souls, is as incomprehensible to us as that of eternity; what a profound thought, which even our imagination cannot embrace! Let us admit, however, for a moment, that all the operations of our souls are determined by some impulsion, whatever it may be, we shall still be struck with the absolute difference which exists, according to our knowledge between the regular movements of matter, and the almost infinite and unaccountable emotions of our hearts and minds; so variable and so differently modified, that the attention is lost in the examination of them. And after having vainly endeavoured to conceive the union established between our thoughts and exterior objects, we have still to form an idea of the actions of these thoughts on themselves, their progression and connection; our mind led astray, lost in such a meditation, leaves us only a consciousness of our weakness, and we feel, that there is an intellectual altitude which the human faculties can never reach.