Monads

Leibniz's best known contribution to <a href="https://en.wikipedia.org/wiki/Metaphysics" title="Metaphysics">metaphysics</a> is his theory of <a href="https://en.wikipedia.org/wiki/Monad%28philosophy%29" title="Monad (philosophy)">monads</a>, as exposited in <a href="https://en.wikipedia.org/wiki/Monadology" title="Monadology">Monadologie</a>. According to Leibniz, monads are <a href="https://en.wikipedia.org/wiki/Elementary_particles" class="mw-redirect" title="Elementary particles">elementary particles</a> with blurred perceptions of one another. Monads can also be compared to the corpuscles of the <a href="https://en.wikipedia.org/wiki/Mechanical_Philosophy" class="mw-redirect" title="Mechanical Philosophy">Mechanical Philosophy</a> of René Descartes and others. Monads are the ultimate elements of the <a href="https://en.wikipedia.org/wiki/Universe" title="Universe">universe</a>. The monads are "substantial forms of being" with the following properties: they are eternal, indecomposable, individual, subject to their own laws, un-interacting, and each reflecting the entire universe in a <a href="https://en.wikipedia.org/wiki/Pre-established_harmony" title="Pre-established harmony">pre-established harmony</a> (a historically important example of <a href="https://en.wikipedia.org/wiki/Panpsychism" title="Panpsychism">panpsychism</a>). Monads are centers of <a href="https://en.wikipedia.org/wiki/Force" title="Force">force</a>; substance is force, while <a href="https://en.wikipedia.org/wiki/Space" title="Space">space</a>, <a href="https://en.wikipedia.org/wiki/Matter" title="Matter">matter</a>, and <a href="https://en.wikipedia.org/wiki/Motion%28physics%29" title="Motion (physics)">motion</a> are merely phenomenal.

The <a href="https://en.wikipedia.org/wiki/Ontology" title="Ontology">ontological</a> essence of a monad is its irreducible simplicity. Unlike atoms, monads possess no material or spatial character. They also differ from atoms by their complete mutual independence, so that interactions among monads are only apparent. Instead, by virtue of the principle of pre-established harmony, each monad follows a preprogrammed set of "instructions" peculiar to itself, so that a monad "knows" what to do at each moment. By virtue of these intrinsic instructions, each monad is like a little mirror of the universe. Monads need not be "small"; e.g., each human being constitutes a monad, in which case <a href="https://en.wikipedia.org/wiki/Free_will" title="Free will">free will</a> is problematic.

Monads are purported to have gotten rid of the problematic:

<ul>

<li>interaction between <a href="https://en.wikipedia.org/wiki/Mind" title="Mind">mind</a> and matter arising in the system of <a href="https://en.wikipedia.org/wiki/Descartes" class="mw-redirect" title="Descartes">Descartes</a>;</li>

<li>lack of <a href="https://en.wikipedia.org/wiki/Principle_of_individuation" title="Principle of individuation">individuation</a> inherent to the system of <a href="https://en.wikipedia.org/wiki/Spinoza" class="mw-redirect" title="Spinoza">Spinoza</a>, which represents individual creatures as merely accidental.</li>

</ul>