Part 1

ESSAYS

ON THE

USE AND LIMIT

OF THE

IMAGINATION IN SCIENCE.

JOHN TYNDALL, LL.D., F.R.S.

LONDON: LONGMANS, GREEN, AND CO. 1870.

EXPLANATORY NOTE.

To a Second Edition of a Discourse on the Scientific Use of the Imagination, delivered before the British Association at Liverpool on September 16, 1870, are here added an Address on the Limit of the Imagination in Science, delivered before the Mathematical and Physical Section of the Association at Norwich on August 19, 1868, and a short Essay, entitled ‘Earlier Thoughts.’

The Address and the Essay were meant to be brief, but definite statements of the relation of Life and Consciousness to Matter and Force.

As in the case of the recent Discourse, opinion was divided with regard to the objects and merits of the Norwich Address. On the one hand, two eminent clergymen, one of the Church of England, the other a Dissenter, proposed and seconded respectively a vote of thanks, which was liberally carried by the section; on the other hand, I was publicly warned that, as a consequence of my impiety, the bolts of heaven were in a state of potential suspension above my head, ready to descend if further drawn upon.

My main object, both at Norwich and at Liverpool, was, firstly, to dissipate the repugnance, and indeed terror, which in many minds are associated with the thought that science has abolished the mystery of man’s relation to the universe; and, secondly, to remove the hindrance which popular notions regarding the origin of life oppose to legitimate scientific speculation.

ATHENÆUM CLUB: November 1870.

CONTENTS.

PAGE

PROS AND CONS TOUCHING THE FIRST EDITION 1

SCIENTIFIC USE OF THE IMAGINATION 13

SCIENTIFIC LIMIT OF THE IMAGINATION 52

EARLIER THOUGHTS 66

PROS AND CONS

TOUCHING THE FIRST EDITION.

From the TIMES, Sept. 19, 1870.

THE GLORY of a Natural Philosopher appears to depend less on the power of his imagination to explore minute recesses or immeasurable space than on the skill and patience with which, by observation and experiment, he assures us of the certainty of these invisible operations. Newton’s glory is founded, not on the sudden imagination by which he leapt ‘from a falling apple to a falling moon,’ but on that astonishing tenacity of investigation by which he reduced his guesses to moral certainties, and enabled us to witness a practical verification of his laws in every almanack we use. When the movements of the heavenly bodies have been discovered by this laborious process, the imagination is excellently employed in picturing to the mind’s eye what transcends the physical vision; and, perhaps, the labour of the investigation itself would be unendurable unless the attention could be relieved by the constant pictorial aid afforded by the imagination....

In a word, it seems to us worth consideration whether that use of the imagination in Natural Philosophy of which the Professor speaks needed any encouragement at the present day. The discoveries of science have been so astonishing, the new worlds they have opened to us are so vast, that there is, perhaps, more danger of our imagination being exercised too freely than of its not being exercised sufficiently upon them. No one will dispute the claim of the Professor to be one of the privileged spirits of whom he speaks, if there are any such, and he proceeds accordingly to exercise his imagination, not upon the little germ-cells, but upon that vast primordial nebulous envelope out of which, according to the opinion to which some philosophers incline, all the infinite complexity of the existing world has been developed. We are not privileged spirits, and we own ourselves not altogether able to follow him when he leads us into the imaginary realms of the original chaos. He confesses that Mr. Darwin ‘has drawn heavily upon time and adventurously upon matter.’ We ask ourselves again whether we are listening to one experimental philosopher describing the achievements of another experimental philosopher. We had been under the impression that Natural Philosophers drew no bills. We do not presume to say one word about the Evolution Hypothesis. We neither affirm nor deny that Professor Tyndall existed in a nebulous state an infinite number of centuries ago. We only venture to suggest that when the British Association amuse the public with these speculations they are illustrating, not the scientific use of the imagination, but the imaginative use of science.

From the SATURDAY REVIEW, Sept. 24, 1870.

Here, too, we question whether Sir William Thomson will be content with this definition of the process by which he has been guided to his most recent advance in molecular physics. In the splendid series of inductions verified step after step by rigorous experiment and observation, and kept in exactest continuity by the chain of mathematical evolution, is imagination the faculty to which are to be given the chief honours of this conquest of a new realm of physics? This would surely be to force upon us a new and arbitrary classification or analysis of the powers of the intellect. If we follow Professor Tyndall himself through the masterly train of reasoning whereby he leads us to the laws of reflection and transmission of light as the cause of the azure of the firmament, is what we admire the leap of imagination, or the firmly balanced and duly graduated tread of a mind trained in the discipline of logic, and careful to plant every step on the assured ground of fact or experience? It is simply a misnomer to apply the name of imagination to the process or the faculty to which this onward march into the realm of unexplored nature is really due. As well describe as a triumph of the imagination the connected and organized plan of the great strategist which has drawn round Paris a living cordon of 300,000 men.

From a Lecture addressed to Teachers at the South Kensington Museum, April 30, 1861, by J. TYNDALL.

Here, then, is an exhibition of power which we can call forth or cause to disappear at pleasure. We magnetize our strip of steel by drawing it along the pole of a magnet; we can demagnetize it, or reverse its magnetism, by properly drawing it along the same pole in the opposite direction. What, then, is the real nature of this wondrous change? What is it that takes place among the atoms of the steel when the substance is magnetized? The question leads us beyond the region of sense, and into that of imagination. This faculty, indeed, is the divining rod of the man of science. Not, however, an imagination which catches its creations from the air, but one informed and inspired by facts, capable of seizing firmly on a physical image as a principle, of discerning its consequences, and of devising means whereby these forecasts of thought may be brought to an experimental test. If such a principle be adequate to account for all the phenomena, if from an assumed cause the observed facts necessarily follow, we call the assumption a theory, and once possessing it, we can not only revive at pleasure facts already known, but we can predict others which we have never seen. Thus, then, in the prosecution of physical science, our powers of observation, memory, imagination, and inference, are all drawn upon. We observe facts and store them up; imagination broods upon these memories, and by the aid of reason tries to discern their interdependence. The theoretic principle flashes, or slowly dawns upon the mind, and then the deductive faculty interposes to carry out the principle to its logical consequences. A perfect theory gives dominion over natural facts; and even an assumption which can only partially stand the test of a comparison with facts, may be of eminent use in enabling us to connect and classify groups of phenomena.