The Lamarck manuscripts at Harvard / edited by William Morton Wheeler and Thomas Barbour.

  • Jean-Baptiste de Lamarck
Date:
1933
Catalogue details

Licence: Public Domain Mark

Credit: The Lamarck manuscripts at Harvard / edited by William Morton Wheeler and Thomas Barbour. Source: Wellcome Collection.

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    the enlightenment of our century should no longer permit us to retain. Some animals, to be sure, and those the most per¬ fect among the vertebrates, are endowed with the faculty of intelligence, have ideas and passions, com¬ pare certain objects with one another and then form judgments, perform acts of volition and therefore act and move voluntarily; but observation proves that they rarely exercise these faculties, that most of their actions originate in the powers of their internal feeling, and that the emotions of this feeling are the immediate source of their actions. It is not correct, therefore, to say that all animals are intelligent beings, that they exhibit judgments, acts of volition and voluntary movements. It would be one of the greatest absurdities to say that the Monad [Amoeba] thinks, judges, wills and directs by its volition all the contractions and other movements which we observe. Let us see whether the faculty of sensation is really a property of all animals. First, it is now established that sensations are pro¬ duced only by means of the nervous system. It there¬ fore follows that an animal without nerves cannot feel. It is established, furthermore, that the nervous sys¬ tem is not the exclusive organ of sensation, since this system is at the same time essential for muscular movement and for the maintenance of the functions of the organs within the organism of which it forms a part. There are, therefore, several kinds of func-