_The Idea, how awakened_--_How come we by our Idea of Space?_--Sense gives us our first knowledge of matter, as extended, etc., and so furnishes the _occasion_ on which the idea of space is first awakened in the mind. In this sense, and no other, does it originate in sensation or experience. It is a simple idea, _logically_ prior to experience, because the very notion of matter _presupposes_ space; yet, _chronologically_, as regards the matter of development in the mind, subsequent to experience and cognizance of matter. II. TIME. _Idea and Definition._--What we have said of space will enable us better to understand what is the nature of that analogous and kindred conception of the mind, in itself so simple, yet so difficult of definition and explanation--_Time._ The remarks already made, respecting space, will almost equally apply to this subject also. Space, we defined as the _condition of being, regarded as extended, material_. Time is the _condition of being, regarded as in action, movement, change_. Sense informs us not only of magnitudes, extensions, material objects, and existences, as around us in nature, but of movements and changes continually taking place among these various existences; as _extension_ is essential to those material forms, so _succession_ is essential to these movements and changes; they cannot take place, nor be conceived to take place, without it; and as space is involved in, and given along with, the very idea of _extension_, so time is involved in, and given along with, the very idea of _succession_. Time, then, is the condition of action, movement, change, event, as space is of extended and material existence. It is that which is required in order that something should _take place_ or occur, just as space is that which is required in order that something should exist as material and having form. As space gives us the question _where_, time gives us the question _when_. It is the place of events, as space is of forms. _Brown's View._--Dr. Brown defines time to be the mere relation of one event to another, as prior and subsequent. It follows, from this view, that if there were no _events_, then no _time_, since the latter is a mere relation subsisting among the former. Is this so? No doubt we derive our _idea_ of time from the succession of events; but is time merely an idea, merely a conception, merely a relation, or has it reality out of and aside from our mind's conceiving it, and independent of the series of events that take place in it?