As reason develops in man, instinct plays a less important part; whereas a cat chases a mouse, a bird flies, and fish swim by instinct from their birth to their last day; and the actions of ants, bees, and moles, do not cease to amaze us, because they are inseparable from their structure and their vital functions. The natural impulses which guide birds and insects in making their nests, hives, and storehouses, cocoons of silk with which they have so enriched our world and theirs, are the results of constant and repeated acts, during the course of innumerable generations. The fact of not distinguishing the instinct which is in man from that found in animals and thus attributing man’s conscious acts to the natural leanings which guide unconscious creatures, has perhaps caused Renan to assert that the monotheistic tendency of the Semitic race belongs to it by a religious instinct. It is certain that impressions are received both by man and by animals; with both the knowledge of objects proceeds from the impressions made on the senses, thus transmitting the image to the intelligence; but there the likeness ends; the capacities differ. The animal remains the slave--in every sense of the word--of his organs; the sight of a bone to gnaw, the corner in which he lies, the signs of friendship that he receives from human beings, call forth in a dog a chain of feelings taking the place of the chain of ideas called out in man. Man’s capabilities of introducing intermediaries between the intention and the fulfilment of his object witness to his wideness of mind, his experience of the past and prevision of the future; all those things that he owes to his power of imagination and conception even in the case of things having no real existence, or which do not exist as yet; he reproduces at will the outward likeness of what is not at the moment before him. Thus man who names an object, _thinks_ it; but the animal from not possessing language cannot _think_ it and cannot reproduce it when out of its sight. The use or non-use of tools creates a great gulf between man and the brutes. The most intelligent animal, a monkey of a high order, never uses a tool--even the most primitive--to accomplish his will; no one can ascribe to the animal creative actions, that is, it does not fashion an implement that it may attain another end; it has never been known to carry an object from one spot to another that it might act as a ladder to bring the animal nearer to the fruit it desired to reach.