A Law of Acceleration, Henry Adams, 1904
1. Images are not arguments, rarely even lead to proof, but the mind craves them, and, of late more than
2. ever, the keenest experimenters find twenty images better than one, especially if contradictory;
3. since the human mind has already learned to deal in contradictions.
4. The image needed here is that of a new center, or preponderating mass, artificially introduced on
5. earth in the midst of a system of attractive forces that previously made their own equilibrium, and
6. constantly induced to accelerate its motion till it shall establish a new equilibrium. A dynamic theory
7. would begin by assuming that all history, terrestrial or cosmic, mechanical or intellectual, would be
8. reducible to this formula if we knew the facts.
9. For convenience, the most familiar image should come first; and this is probably that of the comet, or
10. meteoric streams, like the Leonids and Perseids; a complex of minute mechanical agencies, reacting
11. within and without, and guided by the sum of forces attracting or deflecting it. Nothing forbids one
12. to assume that the man-meteorite might grow, as an acorn does, absorbing light, heat, electricity, –
13. or thought; for, in recent times, such transference of energy has become a familiar idea; but the
14. simplest figure, at first, is that of a perfect comet – say that of 1843, – which drops from space, in a
15. straight line, at the regular acceleration of speed, directly into the sun, and after wheeling sharply
16. about it, in heat that ought to dissipate any known substance, turns back unharmed, in defiance of
17. law, by the path on which it came. The mind, by analogy, may figure as such a comet, the better
18. because it also defies law.
19. Motion is the ultimate object of science, and measures of motion are many; but with thought as
20. with matter, the true measure is mass in its astronomic sense — the sum or difference of attractive
21. forces. Science has quite enough trouble in measuring its material motions without volunteering
22. help to the historian, but the historian needs not much help to measure some kinds of social
23. movement; and especially in the nineteenth century, society by common accord agreed in
24. measuring its progress by the coal-output. The ratio of increase in the volume of coal-power may
25. serve as dynamometer.
26. The coal-output of the world, speaking roughly, doubled every ten years between 1800 and 1900,
27. in the form of utilized power, for the ton of coal yielded three or four times as much power in 1900
28. as in 1840. Rapid as this rate of acceleration in volume seems, it may be tested in a thousand ways
29. without greatly reducing it. Perhaps the ocean steamer is nearest unity and easiest to measure, for
30. anyone might hire, in 1905, for a small sum of money, the use of 30,000 steam-horse-power to cross
31. the ocean, and by halving this figure every ten years, he got back to 234 horse power for 1835,
32. which was accuracy enough for his purposes. Since 1800 scores of new forces had been
33. discovered; old forces had been raised to higher powers, as could be measured in the navy-gun;
34. great regions of chemistry had been opened up, and connected with other regions of physics.
35. Within ten years a new universe of force had been revealed in radiation. Complexity had
36. extended itself on immense horizons, and arithmetical ratios were useless for any attempt at
37. accuracy. The force evolved seemed more like explosion than gravitation, and followed closely the
38. curve of steam; but, at all events, the ten-year ratio seemed carefully conservative. Unless the
39. calculator was prepared to be instantly overwhelmed by physical force and mental complexity, he
40. must stop there.
41. The science of prehistoric man has no value except to prove that the law went back into indefinite
42. antiquity. A stone arrowhead is as convincing as a steam-engine. The values were as clear a hundred
43. thousand years ago as now, and extended equally over the whole world. The motion at last became
44. infinitely slight, but cannot be proved to have stopped. The motion of Newton’s comet at aphelion may be
45. equally slight. To evolutionists may be left the processes of evolution; to historians the single interest is
46. the law of reaction between force and force, — between mind and nature, — the law of progress.
Adams, Henry. "A Law of Acceleration." Bartleby.com. N.p., n.d. Web. 4 May 2016.
The shift from the first paragraph (lines 1-3) to the second (lines 4-8) moves from