_Correctness of this Enumeration._--That the truths now specified are in some sense primary, that they are generally admitted and acted upon, among men, without process of reasoning, and that, when stated, they command the universal and instant assent of even the untaught and unreflecting mind, there can be little doubt. Whether, in all cases, however, they come strictly under the rules and criteria now given; whether, for example, our own existence and identity are primary data of consciousness; or whether, on the contrary, they are not _inferred_ from the existence of those thoughts and feelings of which we are directly conscious, as, for example, in the famous argument of Descartes, _Cogito, ergo sum_, may admit of question. § II.--INTUITIVE CONCEPTIONS. Of the results or operations of the faculty under consideration, we have considered, as yet, only that class which may be designated as primary _truths_, in distinction from primitive or intuitive _conceptions_. To this latter class let us now direct our attention. _Proposed consideration of some of the more important._--Without undertaking to give a complete list of our original or intuitive conceptions, there are certain of the more important, which seem to require specific consideration. Such are the ideas of space, time, identity, cause, the beautiful, the right--ideas difficult to define and explain, but, on that account, requiring the more careful investigation. Let us, then, take up these conceptions one by one, and inquire more particularly into their nature. I. _Space._ _Subjective View._--What is space? Is it a mere idea, a mere conception of the mind, or has it reality? This is a question which has much perplexed philosophers. Kant and his school regard both time and space as merely subjective, mere conceptions or forms which the mind imposes upon outward things, having no reality, save as conceptions, or laws of thought. _Opposite View._--On the other hand, if we make space a reality, and not a mere conception, what is it, and where is it? Not matter, and yet real, a something which exists, distinct from matter, and yet not mind. Pressed with these difficulties, some distinguished and acute writers have resolved time and space into qualities of the one infinite and absolute Being, the divine mind. Such was the view of Clarke and Newton, a view favored also by a recent French writer of some note--C. H. Bernard, Professor of Philosophy in the Lycée Bonaparte. _A middle Ground._--These must be regarded as, on either hand, extreme views. But is there a middle ground possible or conceivable? Let us see. What, then, is the simple idea of space? What mean we by that word?