escribed an imaginary
apparatus (by means of which, he said, people could converse at a
distance) for the aid of lovers who, by the connection of their
movements, would cause a needle to move about a dial on which would be
written the letters of the alphabet; and the drawing accompanying the
text is almost a picture of Breguet's telegraph." But the author
considered it impossible "in the absence of lovers having such
ability."[128]

Mechanical inventions that fail correspond to erroneous or unverified
scientific hypotheses. They do not emerge from the stage of pure
imagination, but they are instructive to the psychologist because they
give in bare form the initial work of the constructive imagination in
the technical field.

There still remain the requirements of reasoning, of calculation, of
adaptation to the properties of matter. But, we repeat, this determinism
has several possible forms--one can reach the same goal through
different means. Besides, these determining conditions are not lacking
in any type of imagination; there is only a difference as between lesser
and greater. Every imaginative construction from the moment that it is
little more than a group of fancies, a spectral image haunting a
dreamer's brain, must take on a body, submit to external conditions on
which it depends, and which materialize it somewhat. In this respect,
architecture is an excellent example. It is classed among the fine arts;
but it is subject to so many limitations that its process of invention
strongly resembles technical and mechanical creations. Thus it has been
possible to say that "Architecture is the least personal of all the
arts." "Before being an art it is an industry in the sense that it has
nearly always a useful end that is imposed on it and rules its
manifestations. Whatever it builds--a temple, a theater, a palace--it
must before all else subordinate its work to the end assigned to it in
advance. This is not all:--it must take account of materials, climate,
soil, location, habits--of all things that may require much skill, tact,
calculation, which, however, do not interest art as such, and do not
permit architecture to manifest its purely esthetic qualities."[129]

Thus, at bottom, there is an identity of nature between the constructive
imagination of the mechanic and that of the artist: the difference is
only in the end, the means, and the conditions. The formula, _Ars homo
additus naturae_, has been too often restr