The privileged rules of the policy of the old world imposed upon themselves a limit to excessive power, and used the saying, _Noblesse oblige_. A new motto might be proposed to the builders and destroyers of Governments in our day, which would be equally noble and might be more fertile of results—_Progrès oblige_.—_Nineteenth Century._ ORGANIC NATURE’S RIDDLE. BY ST. GEORGE MIVART. Amongst the many sagacious sayings of the patient and profound thinkers of Germany, not the least noteworthy was Schelling’s affirmation that the phenomena of instinct are some of the most important of all phenomena, and capable of serving as a very touch-stone whereby the value of competing theories of the universe may be effectually tested. His prescience has been justified by our experience. The greatest scientific event of the present time is the wide acceptance of the theory of evolution, and its use as a weapon of offence and defence. It is used both against the belief that intelligent purpose is, as it were, incarnate in the living world about us, and also in favor of a merely mechanical theory of nature. Now it would be difficult to find a more searching test of that theory’s truth than is supplied by a careful study of instinct. The essence of that view of nature which is associated with the name of Professor Haeckel,[1] a negation of the doctrine of final causes and an assertion of what he calls “Dysteleology,” that is, the doctrine of the purposelessness of the organs and organisms which people a purposeless planet. That doctrine may be called the gospel of the irrationality of the universe, and it is a doctrine to which a proof of the real existence of such a thing as “instinct” must necessarily be fatal. Instinct has been defined[2] as a “special internal impulse, urging animals to the performance of certain actions which are useful to them or to their kind, but the use of which they do not themselves perceive, and their performance of which is a necessary consequence of their being placed in certain circumstances.” Such an impulse is always understood to be the result of sensations: actions which take place in response to _unfelt_ stimuli being referred, not to instinct, but to what is termed _reflex action_. In such action it is commonly supposed that the mechanism of a living body occasions a prompt responsive muscular movement upon the occurrence of some unfelt stimulation of the nervous system. The nervous system, or total mass of nerve-stuff—which is technically called “nerve-tissue”—in the body of an animal, such as a beast, bird, reptile, or fish, is composed of two parts or divisions. One of these divisions consists of a voluminous and continuous mass—the brain and spinal cord (or spinal marrow), which form what is called the central part of the nervous system. The second division consists of a multitude of white threads or cords—the nerves, which form what is called the peripheral part of the nervous system.