Natural Philosophy is a public-domain classic of science by Wilhelm Ostwald.
The complete text is on this page and the chapter pages below — all 8 chapters, about 48,246 words (~4 hours of reading), free to read online with no signup. Chapters include “PART I. General Theory of Knowledge 11”, “PART II. Logic, the Science of the Manifold, and Mathematics 61”, “PART III. The Physical Sciences 127”, and more.
Short, fact-checked Wunder courses related to Natural Philosophy — free to read, no signup. Or browse every course.
GENERAL THEORY OF KNOWLEDGE 11
1. The Formation of Concepts 11
2. Science 13
3. The Aim of Science 13
4. Concrete and Abstract 16
5. The Subjective Part 17
6. Empirical Concepts 18
7. Simple and Complex Concepts 19
8. The Conclusion 24
9. The Natural Laws 28
10. The Law of Causation 31
11. The Purification of the Causal Relation 34
12. Induction 38
13. Deduction 40
14. Ideal Cases 44
15. The Determinateness of Things 47
16. The Freedom of the Will 50
17. The Classification of the Sciences 53
18. The Applied Sciences 57
LOGIC, THE SCIENCE OF THE MANIFOLD, AND MATHEMATICS 61
19. The Most General Concept 61
20. Association 63
21. The Group 65
22. Negation 68
23. Artificial and Natural Groups 69
24. Arrangement of the Members 75
25. Numbers 78
26. Arithmetic, Algebra, and the Theory of Numbers 79
27. Co-ordination 80
28. Comparison 82
29. Numbers 85
30. Signs and Names 86
31. The Written Language 89
32. Pasigraphy and Sound Writing 92
33. Sound Writing 96
34. The Science of Language 97
35. Continuity 101
36. Measurement 107
37. The Function 109
38. The Application of the Functional Relation 112
39. The Law of Continuity 113
40. Time and Space 118
41. Recapitulation 124
THE PHYSICAL SCIENCES 127
42. General 127
43. Mechanics 128
44. Kinetic Energy 132
45. Mass and Matter 136
46. Energetic Mechanics 138
47. The Mechanistic Theories 140
48. Complementary Branches of Mechanics 144
49. The Theory of Heat 147
50. The Second Fundamental Principle 150
51. Electricity and Magnetism 154
52. Light 156
53. Chemical Energy 159
THE BIOLOGIC SCIENCES 163
54. Life 163
55. The Storehouse of Free Energy 168
56. The Soul 171
57. Feeling, Thinking, Acting 174
58. Society 179
59. Language and Intercourse 182
60. Civilization 184
INDEX 187
INTRODUCTION
Natural science and natural philosophy are not two provinces mutually exclusive of each other. They belong together. They are like two roads leading to the same goal. This goal is the domination of nature by man, which the various natural sciences reach by collecting all the individual actual relations between the natural phenomena, placing them in juxtaposition, and seeking to discover their interdependence, upon the basis of which one phenomenon may be foretold from another with more or less certainty. Natural philosophy accompanies these specialized labors and generalizations with similar labors and generalizations, only of a more universal nature. For instance, while the science of electricity, as a branch of physics, deals with the relation of electrical phenomena to one another and to phenomena in other branches of physics, natural philosophy is not only concerned with the question of the mutual connection of all physical relations, but also endeavors to include in the sphere of its study chemical, biological, astronomical, in short, all the known phenomena. In other words, natural philosophy is the most general branch of natural science.
Here two questions are usually asked. First, how can we define the boundary line between natural philosophy and the special sciences, since, obviously, sharp lines of demarcation are out of the question? Secondly, how can we investigate and teach natural philosophy, when it is impossible for any one person to master all the sciences completely, and so obtain a bird's-eye view of the general relations between all the branches of knowledge? To the beginner especially, who must first learn the various sciences, it seems quite hopeless to devote himself to a study that presupposes a command of them.
Since a discussion of the two questions will afford an excellent preliminary survey of the work in hand, it will be well to consider them in detail. In the first place, the lack of complete and precise boundary lines is a general characteristic of all natural things, and science is a natural thing. If, for instance, we try to differentiate sharply between physics and chemistry, we are met with the same difficulty. So also in biology if we try to settle beyond the shadow of a doubt the line of separation between the animal and the vegetable kingdoms.
If, despite this well-known impossibility, we consider the division of natural things into classes and orders as by no means useless and do not discard it, but regard it as an important scientific work, this is practical proof that such classification preserves its essential usefulness, even if it does not attain ideal definiteness. For, this imperfection notwithstanding, classification reaches its end, which is a comprehensive view, and thus a mastery, of the manifoldness of phenomena. For example, with the overwhelming majority of organic beings there is no doubt whether they are animals or plants. Similarly, most phenomena of inorganic nature can readily be designated as physical or chemical. For all such cases, therefore, the existing classification is good and useful. The few cases presenting difficulty may very well be considered by themselves wherever they occur, and we need merely take cognizance of them here. It follows from this, to be sure, that classification will be all the better fitted to its purpose the less frequently such doubtful cases arise, and that we have an interest in repeatedly testing existing classifications with a view to finding out if they cannot be supplanted by more suitable ones.
In these matters it is much the same as when we look upon the waves on the surface of a large body of water. Our first glance tells us that a number of waves are rolling there; and from a point giving us a sufficiently wide outlook, we can count them and gauge their width. But where is the line of division between one wave and the next? We undoubtedly see one wave following another, yet it is impossible for us to indicate precisely the end of one and the beginning of the next. Are we then to deduce that it is superfluous or unfeasible to designate the waves as different? By no means. On the contrary, in strictly scientific work we will endeavor to find some suitable definition of the boundary line between two consecutive waves. It may then be called an arbitrary line, and in a degree arbitrary it will certainly be. But to the investigator this does not matter. What concerns him is, if, with the help of this definition, wave lengths can be unequivocally determined, and if this is possible, he will use the definition as suitable to the purposes of science, without dismissing from his mind the idea that possibly some other definition may provide an even easier or sharper determination. Such an one he would instantly prefer to the old one.
Thus we see that these questions of classification are not questions of the so-called "essence" of the thing, but pertain merely to purely practical arrangements for an easier and more successful mastery of scientific problems. This is an extremely important point of view, much more far-reaching than is apparent here at its first application.
As to the second objection, I will admit its validity. But here, too, we have a phenomenon appearing in all branches and forms of science. Therefore we must familiarize ourselves with it in advance. Science was created by man for man's purposes, and, consequently, like all human achievements, possesses the indestructible quality of imperfection. But the mere fact that a successful working science exists, with the help of which human life has been fundamentally modified, signifies that the quality of incompleteness in human learning is no hindrance to its efficiency. For what science has once worked out always contains a portion of truth, hence a portion of efficiency. The old corpuscular theory of light, which now seems so childishly incomplete to us, was adequate, none the less, for satisfactorily explaining the phenomena of reflection and refraction, and the finest telescopes have been built with its help. This is due to the true elements in it, which taught us correctly to calculate the direction of rays of light in reflection and refraction. The rest was merely an arbitrary accessory which had to fall when new, contradictory facts were discovered. These facts could not have been taken into consideration when the theory was propounded, because they were not yet known. But when the corpuscular theory of light was replaced by the theory of waves of an elastic ether, geometric optics at first remained quite unchanged, because the theory of straight lines of rays could be deduced from the new views also, though not so easily and smoothly. And geometric optics was then concerned with nothing but these straight lines, in no wise with the question of their propagation. It did not become clear until recently that this conception of straight lines of rays is incomplete, though, it is true, it made a first approach toward the presentation of actual phenomena. It fails when it comes to characterize the behavior of a pencil of rays of large aperture. The old idea of a straight line of rays was to be replaced by a more complex concept with more varied characteristics, namely, the wave-surface. The greater variety of this concept renders possible the presentation of the greater variety of the optical phenomena just mentioned. And from it proceed the very considerable advances that have been made, since the new theory was propounded, in optical instruments, especially the microscope and the photographic objective, for the purposes of which pencils of rays of large aperture are required. The astronomic objective with its small angle of aperture has not undergone particularly important improvements.
Continue reading Natural Philosophy free in the Wunder reader →
The Wunder Library · Learn anything · Home — complete public-domain books, free to read, with narration and illustrations. Natural Philosophy is in the public domain.