The Industries of Animals

by Frédéric Houssay

The naturalist of to-day usually lives more in the laboratory than in the country. Occasional expeditions to the coast or dredgings are the only links that attach him to nature; the scalpel and the microtome have replaced the collector’s pins, and the magnifying glass gives place to the microscope. When the observer begins to pursue his studies in the laboratory he no longer cares to pass the threshold. He has still so much to learn concerning the most common creatures that it seems useless to him to waste his time in seeking those that are rarer, unless he takes into account the unquestionable pleasure of rambling through woods or along coasts; — but such a consideration does not belong to the scientific domain.

A change of conditions of this nature does not suffice to create a science. To take away from a study all that rendered it pleasant and easy, and to make it the property of a small coterie, when it was formerly accessible to all, is not sufficient to render it scientific. It is a fatality rather than a triumph to have undergone such a change. The change is an effect rather than a cause.

When little or nothing was known it was necessary to begin by examining the phenomena which first met the eyes of the observer, such as the customs of animals and the characters which distinguished them from each other. Their differences and resemblances were studied; they were formed into groups, classed and arranged in an order recalling as much as possible their natural relations. In classifying it is impossible to consider all the facts or the result would be chaos; it is necessary to choose the characters and to give preponderance to certain of them. This sorting of characters has been executed with the sagacity of genius by the illustrious naturalists of the last century and the beginning of the present. But the frames which they have traced are fixed and rigid; nature with her infinite plasticity escapes from them. We render a great homage to the classifiers when we say that they have confined the facts as closely as it is possible to do. The catalogues which they have prepared are of a utility which is unquestionable, although their rôle is to be useful only; we cannot pretend to make them the expression, the symbol, the formula in which all natural phenomena are to be enclosed. To confound classification with science is to confound the lever with the effect which we expect from it.

Curiosity, moreover, always impels towards that which is least known. External appearances having been studied, the form and function of internal organs were investigated. Physiology and comparative anatomy were born and developed; researches abounded and observers abandoned the field for the laboratory.

The difference in methods of research and the pushing of precision to its extreme limits — an inevitable result of the different nature of the observations to be made — did not however yet render legitimate the claim for natural studies to be called “science.”

Natural history and the natural sciences. — A more important event has taken place. The ancient naturalists, like their contemporaries, had firm beliefs which they used as unquestionable principles for the comprehension of all facts. The explanation of an observation was ready in advance. The study of facts invariably brought to the pen of the writer the same enthusiastic admiration of the marvellous part played by Providence in nature.[1] The phenomena in which this action was not strikingly apparent were merely described without any attempt to relate them with each other, or with the other facts. A hypothesis which left a great number of facts without explanation was necessarily insufficient. The descriptions, in spite of all their individual interest, did not constitute a homogeneous whole, a science. They were merely a collection of more or less natural histories.

Science only begins on the day when we have found the simple theory which binds together all the facts at that time known, without of course prejudicing the future. As the number of acquired facts increases, if the theory in question continues to explain the new as it explained the old, the science becomes more firmly established. If we can imagine a time arriving when all the possible phenomena are known, and the existing hypothesis still explains them, nothing henceforth can overturn it, the science is completed. That is the simple case in which a theory has been victorious; but if it is contradicted by a single well-authenticated fact it must fall or become modified. The more things a theory explains in the present the more chance it has of success in the future. It is still only a matter of chances, for the theory is always at the mercy of unforeseen observation, which may rudely overthrow it.

There is no theory which must not be modified constantly, at least in its details. To render it more and more general by successive improvements is the aim to be pursued. A collection of studies constitutes a science when a hypothesis has arisen already sufficiently strong to oblige us to refer to it all new acquisitions, and to compel us to see if they fortify or oppose it.

It would indeed be a narrow conception if we were to consider as scientific the partisans of the theory alone; more than anywhere else discussion is fruitful in the natural sciences; and if it is necessary to be constantly preoccupied with the general ideas of the day, it is not at all necessary to adhere to them servilely. The naturalists of to-day are in possession of a formula with which we must always preoccupy ourselves; in other words, there are natural sciences.

The theory of Evolution. — This hypothesis which comes before all others is the theory of evolution. This is not the place to expound it, to go over the proofs which have been amassed to build it up, nor the criticisms which have been directed against it. It has to-day come out of the struggle victoriously. A prodigious quantity of facts, of comparative anatomy and of embryology, inexplicable without it, emerge from the chaos and constitute a whole, truly and marvellously homogeneous. Issued from the natural sciences, the doctrine of evolution now overflows them and tends to embrace everything that concerns man: history, sociology, political economy, psychology. The moralists seek, and will surely find, compromises permitting ethical laws to endure the rule of this overwhelming hypothesis.