this dynamically, though certainly not in the sense in which dynamics are to-day understood, viz. as an increase of intensity or as a degree, for he accepts intensity in its truth as universal capacity. Undoubtedly the difference must also be taken as a difference in amount, but not as an increase and decrease, or as an alteration in the absolute quantity of the matter. For here intensity means force, but again not as being a thing of thought separated from matter, but as indicating that if anything has become more intensive, it has had its actuality diminished, having, however, according to Aristotle, attained to a greater capacity. If the intensity is again directed outwards, and compared with other things, it undoubtedly becomes degree, and therefore magnitude immediately enters in. It then is indifferent whether greater intension or greater extension is posited; more air is capable of being warmed to the same degree as less, through the greater intensity of the warmth; or the same air can thereby become intensively warmer. As regards the investigation of time, Aristotle remarks (Phys. IV. 10, 11, 13) that if time is externally (exoterically, ἐξωτερικῶς) regarded, we are inevitably led to doubt (διαπορῆσαι) whether it has any being whatever, or whether it has bare existence, as feeble (μόλις καὶ ἀμυδρῶς) as if it were only a potentiality. “For one part of it was and is not: another part will be and is not as yet; but of these parts infinite and everlasting (ἀεὶ λαμβανόμενος), time is composed. But it now appears that time, if composed of things that are not, may be incapable of existence. And also as regards everything divisible, if it exists, either some or all of its parts must be. Time is certainly divisible; but some of the parts are past, others are future, and no part is present. For the _now_ is no part, since a part has a measure, and the whole must consist of the parts; but time does not appear to consist of the Now.” That is to say, because the Now is indivisible, it has no quantitative determination which could be measured. “Besides it is not easy to decide whether the Now remains, or always becomes another and another. Again, time is not a movement and change, for movement and change occur in that which is moved and changed, or accompany time in its course; but time is everywhere alike. Besides change is swifter and slower, but time is not. But it is not without change and motion” (which is just the moment of pure negativity in the same) “for when we perceive no change, it appears as if no time had elapsed, as in sleep. Time is hence in motion but not motion itself.” Aristotle defines it thus: “We say that time is, when we perceive the before and after in movement; but these are so distinguished that we apprehend them to be another and another, and conceive that there is something between, as a middle. Now when we understand that the extremes of the conclusion are different from the middle, and the