Commentary on Aristotle's Physics

 CONTENTS

 TRANSLATORS' PREFACE

 INTRODUCTION

 BOOK I

 LECTURE 1 (184 a 9-b 14)

 LECTURE 2 (184 b 15-185 a 19)

 LECTURE 3 (185 a 20-b 27)

 LECTURE 4 (185 b 27-186 a 4)

 LECTURE 5 (186 a 5-22)

 LECTURE 6 (186 a 23-b 35)

 LECTURE 7 (187 a 1-10)

 LECTURE 8 (187 a 11-26)

 LECTURE 9 (187 a 27-188 a 18)

 LECTURE 10 (188 a 19-189 a 10)

 LECTURE 11 (189 a 11-b 29)

 LECTURE 12 (189 b 30-190 b 15)

 LECTURE 13 (190 b 16-191 a 22)

 LECTURE 14 (191 a 23-b 34)

 LECTURE 15 (191 b 35-192 b 5)

 BOOK II

 LECTURE 1 (192 b 8-193 a 8)

 LECTURE 2 (193 a 9-b 21)

 LECTURE 3 (193 b 22-194 a 11)

 LECTURE 4 (194 a 12-b 15)

 LECTURE 5 (194 b 16-195 a 27)

 LECTURE 6 (195 a 28-b 30)

 LECTURE 7 (195 b 31-196 b 9)

 LECTURE 8 (196 b 10-197 a 7)

 LECTURE 9 (197 a 8-35)

 LECTURE 10 (197 a 36-198 a 21)

 LECTURE 11 (198 a 22-b 9)

 LECTURE 12 (198 b 10-33)

 LECTURE 13 (198 b 34-199 a 33)

 LECTURE 14 (199 a 34-b 33)

 LECTURE 15 (199 b 34-200 b 9)

 BOOK III

 LECTURE 1 (200 b 12-201 a 8)

 LECTURE 2 (201 a 9-b 5)

 LECTURE 3 (201 b 6-202 a 2)

 LECTURE 4 (202 a 3-21)

 LECTURE 5 (202 a 22-b 29)

 LECTURE 6 (202 b 30-203 b 14)

 LECTURE 7 (203 b 15-204 b 3)

 LECTURE 8 (204 b 4-205 a 6)

 LECTURE 9 (205 a 7-206 a 7)

 LECTURE 10 (206 a 8-b 32)

 LECTURE 11 (206 b 33-207 a 31)

 LECTURE 12 (207 a 32-208 a 4)

 LECTURE 13 (208 a 5-24)

 BOOK IV

 LECTURE 1 (208 a 27-209 a 1)

 LECTURE 2 (209 a 2-30)

 LECTURE 3 (209 a 31-210 a 13)

 LECTURE 4 (210 a 14-b 32)

 LECTURE 5 (210 b 33-211 b 4)

 LECTURE 6 (211 b 5-212 a 30)

 LECTURE 7 (212 a 31-b 22)

 LECTURE 8 (212 b 23-213 a 10)

 LECTURE 9 (213 a 11-b 20)

 LECTURE 10 (213 b 30-214 b 11)

 LECTURE 11 (214 b 12-215 a 23)

 LECTURE 12 (215 a 24-216 a 26)

 LECTURE 13 (216 a 27-216 b 20)

 LECTURE 14 (216 b 21-217 b 28)

 LECTURE 15 (217 b 29-218 a 30)

 LECTURE 16 (218 a 31-219 a 1)

 LECTURE 17 (219 a 2-b 8)

 LECTURE 18 (219 b 9-220 a 23)

 LECTURE 19 (220 a 24-b 30)

 LECTURE 20 (221 a 1-222 a 9)

 LECTURE 21 (222 a 10-b 15)

 LECTURE 22 (222 b 16-223 a 15)

 LECTURE 23 (223 a 16-224 a 16)

 BOOK V

 LECTURE 1 (224 a 21-b 34)

 LECTURE 2 (224 b 35-225 b 4)

 LECTURE 3 (225 b 5-226 a 22)

 LECTURE 4 (226 a 23-b 18)

 LECTURE 5 (226 b 19-227 b 2)

 LECTURE 6 (227 b 3-228 a 19)

 LECTURE 7 (228 a 20-229 a 6)

 LECTURE 8 (229 a 7-b 22)

 LECTURE 9 (229 b 23-230 a 18)

 LECTURE 10 (230 a 19-231 a 18)

 BOOK VI

 LECTURE 1 (231 a 21-b 18)

 LECTURE 2 (231 b 19-232 a 18)

 LECTURE 3 (232 a 19-233 a 16)

 LECTURE 4 (233 a 17-b 32)

 LECTURE 5 (233 b 33-234 b 20)

 LECTURE 6 (234 b 21-235 b 5)

 LECTURE 7 (235 b 6-236 b 19)

 LECTURE 8 (236 b 20-237 b 23)

 LECTURE 9 (237 b 24-238 b 22)

 LECTURE 10 (238 b 23-239 b 4)

 LECTURE 11 (239 b 5-240 b 7)

 LECTURE 12 (240 b 8-241 a 26)

 LECTURE 13 (241 a 27-b 20)

 BOOK VII

 LECTURE 1 (241 b 24-242 a 15)

 LECTURE 2 (242 a 16-243 a 2)

 LECTURE 3

 LECTURE 4

 LECTURE 5

 LECTURE 6

 LECTURE 7 (248 a 10-249 a 7)

 LECTURE 8 (249 a 8-b 25)

 LECTURE 9 (249 b 26-250 b 9)

 BOOK VIII

 LECTURE 1 (250 b 11-251 a 7)

 LECTURE 2 (251 a 8-252 a 3)

 LECTURE 3 (252 a 4-b 6)

 LECTURE 4 (252 b 7-253 a 21)

 LECTURE 5 (253 a 22-254 a 2)

 LECTURE 6 (254 a 3-b 6)

 LECTURE 7 (254 b 7-255 a 18)

 LECTURE 8 (255 a 19-256 a 2)

 LECTURE 9 (256 a 3-257 a 34)

 LECTURE 10 (257 a 35-258 a 5)

 LECTURE 11 (258 a 6-b 9)

 LECTURE 12 (258 b 10-259 a 21)

 LECTURE 13 (259 a 22-260 a 19)

 LECTURE 14 (260 a 20-261 a 27)

 LECTURE 15 (261 a 28-b 26)

 LECTURE 16 (261 b 27-262 b 9)

 LECTURE 17 (262 b 10-264 a 7)

 LECTURE 18 (264 a 8-b 8)

 LECTURE 19 (264 b 9-265 a 27)

 LECTURE 20 (265 a 28-266 a 9)

 LECTURE 21 (266 a 10-b 26)

 LECTURE 22 (266 b 27-267 a 21)

 LECTURE 23 (267 a 22-b 26)

 APPENDIX A

 BOOK VII, CHAPTER 2

 BOOK VII, CHAPTER 3

 Footnotes

LECTURE 21 (222 a 10-b 15)

HE COMPARES TIME TO THINGS WHICH ARE IN THE 'NOW'. THE MEANING OF 'NOW' (NUNC), 'THEN' (TUNC), 'PRESENTLY' (IAM), 'LATELY' (MODO), 'LONG AGO' (OLIM), AND 'SUDDENLY' (REPENTE)

             612. After the Philosopher has shown how time is related to things which are in time, he here shows how certain things are named in respect to time by means of diverse relations to the 'now'.

             Concerning this he makes two points. First he explains the meaning of 'now'. Secondly, where he says, ' "At some time" means . . .' (222 a 24), he explains the meaning of certain other things which are determined by the 'now'.

             Concerning the first part he makes two points. First he gives the proper and principal meaning of 'now'. Secondly, where he says, '. . . another is when the time . . .' (222 a 20), he gives a secondary meaning.

             613. Concerning the first part he says three things about the 'now'. The first point is that the 'now' continues past time into the future, insofar as it is the terminus of time, that is, the beginning of the future and the end of the past. However, this is not as clear in regard to the 'now' as it is in regard to a point. For a point is stationary, and therefore can be taken twice, once as a beginning and once as an end. But this does not happen in regard to the 'now', as was said above.

             Secondly, where he says, 'It divides potentially . . .' (222 a 14), he states that time is divided by the 'now' as a line is divided by a point. But the 'now' divides time insofar as it is considered as many in potency, that is, insofar as it is taken separately as the beginning of one time and the end of another. And in this way it is taken as different 'nows'. But insofar as it is taken as joining time and continuing it, it is taken as one and the same.

             He explains this by means of a comparison with mathematical lines in which it is more manifest. In mathematical lines a point which is designated in the middle of a line is not always understood as the same. For insofar as it divides the line, the point which is the end of one line is understood to be different than the point which is the end of the other line. For insofar as lines are actually divided, they are contiguous. And those things are contiguous whose ends are together. But insofar as a point makes the parts of a line continuous, it is one and the same. For those things are continuous whose end is the same. And such is also the case with the 'now' in respect to time. For in one way the 'now' can be taken as a division of time according to potency, and in another way as a common terminus of two times, which joins them and makes them continuous.

             Thirdly, where he says, 'And the dividing . . .' (222 a 18), he states that the 'now' as dividing and continuing time is one and the same in subject but different according to reason [ratio], as is clear from what has been said. And this is one meaning of the 'now'.

             614. Next where he says, '. . . another is when the time . . .' (222 a 20), he gives a secondary meaning of the 'now'.

             He says that there is another meaning of the 'now' besides the terminus of time which continues the past into the future. 'Now' is that time, either in the past or in the future, which is close to the present 'now'. Thus we say, 'He will come now,' because he will come today, and, 'He came now,' because he came today. But we do not say that the Trojan War happened now, or that the flood happened now. For although all time is continuous, not all time is close to the present 'now'.

             615. Next where he says, ' "At some time" means . . .' (222 a 24), he explains certain things which are determined by the 'now'. First he explains the meaning of 'then'.

             Concerning this he makes two points. First he gives the meaning of 'then'. Secondly, he raises a problem where he says, 'But if there be . . .' (222 a 28).

             He says, therefore, first that the term 'then' signifies a time determined by some prior 'now', either close to or removed from the present. For we can say, 'Then Troy was destroyed', or, 'Then the flood occurred'. That which is said to have happened 'then' must be included by some 'now' or preceding instant. For in that 'now', which was in the past, there must be some time of a quantity determined by the present time. And thus it is clear that the term 'then' differs from the second meaning of 'now' in two ways. For 'then' always refers to the past, and it refers to the recent and distant past indifferently. But 'now' refers to recent times, and it refers to the past and the future indifferently.

             616. Next where he says, 'But if there be . . .' (222 a 28), he raises a problem from the above, and answers it.

             He said that a time which is said to be 'then' is included in the time between a past 'now' and the present. Hence any time which is said to be 'then' must be finite. But there is no time which cannot be said to be 'then'. Therefore all time is finite. But every finite time comes to an end. Hence it seems that time ends. But if motion is eternal, and if time is the number of motion, it follows that time does not end. Therefore, if all time is finite, then it will be necessary to say either that there is always a different time or that the same time is repeated over and over again. And this must occur in time as it does in motion. For if there is always one and the same motion, there must be one and the same time. But if there is not one and the same motion, there will not be one and the same time.

             617. Therefore, according to his opinion, motion never began nor will it end, as will be made clear in Book VIII. And thus a motion which is one and the same in species, but not in number, is repeated. For the circular motion which is now is not the same in number as the circular motion which was, but it is the same in species. Nevertheless, the whole of motion is one by continuity, because one circular motion is continued by another, as will be proven in Book VIII. And this must be the same with time as it is with motion.

             Consequently he shows that time will never end.

             It is clear from the above that the 'now' is both a beginning and an end, but not in the same respect. It is an end in respect to the past and a beginning in respect to the future. Thus time is similar to a circle in which concavity and convexity are the same in subject but different in reason [ratio] in respect to diverse things. For the convexity of a circle is found by a comparison to the exterior, and the concavity by a comparison to the interior. Now since there is no time except the 'now', as was said above, it follows that time is always at a beginning and at an end. And because of this time seems to be different, for the 'now' is not the beginning and the end of the same time but of different times. Otherwise opposites would be in the same thing in the same respect. For beginning and end have opposite natures [ratio]. If, therefore, the same thing is a beginning and an end in the same respect, opposites will be in the same thing in the same respect.

             He further concludes from the above that since the 'now' is the beginning and the end of time, time will never end. For there can be no time without a 'now', as was said above, and the 'now' is the beginning of time. Hence time is always in its beginning. But that which is in its beginning is not ending. Therefore time will not end. And for the same reason it can be proven that time did not begin, because the 'now' is the end of time.

             But this argument proceeds on the supposition that motion is eternal, as he says. On this supposition it is necessary to say that any 'now' of time is both a beginning and an end. But if it be said that motion began or will end, then it would follow that there will be a 'now' which is a beginning of time and not an end, and there will be a 'now' which is an end of time and not a beginning, as happens in a line. For if there is an infinite line, any point designated in it will be both a beginning and an end. But in a finite line there is found a point which is only a beginning or only an end. This will be examined further in Book VIII.

             618. Next where he says, ' "Presently" or "just" refers . . .' (222 b 9), he shows what 'just now' means. This expression has the same meaning as the second meaning of 'now'. For that is said to be 'just now' which is close to the indivisible, present 'now', either as part of the future or as part of the past. It is part of the future when one says, 'When will he come?' 'Just now.' For the time in which the future event will occur is near. It is part of the past when it is asked, 'When did you come?' 'I came just now,' is the response. Things which happened long ago we do not describe as 'just now'. Thus we do not say that Troy was destroyed 'just now', for this is removed a great deal from the present 'now'.

             619. Next where he says, ' "Lately," too, refers to . . .' (222 b 13), he explains certain other things which pertain to time.

             He says that the term 'lately' signifies a past which is close to the present 'now'. Thus if it be asked, 'When did he go?' one answers 'lately', if that past time is close to the present 'now'. But we say 'long ago' when the past time is far removed from the present 'now'. Something is said to occur 'suddenly' when the time in which it occurs is not sensible because of its shortness.