A Materialistic Rationalist? Urban Gottfried Bucher’s Defense of Innate Ideas and Mechanism, Added by his Denial of Free Will

Urban Gottfried Bucher is one of the most surprising authors in early German enlightenment and has been rightly celebrated as a materialist and therefore radical thinker. But he did not teach the same kind of materialism as his contemporary Andreas Rüdiger who leaned toward Locke’s empiricism. Bucher is much closer to Hobbes’ mechanical materialism, to Spinoza’s criticism of free will, and to Tschirnhaus’ extending of the mathematical method to natural science. His explanation of the working of the human soul, while materialistic, is rationalistic and mechanical. The difference between the two kinds of materialism becomes crystal-clear in Bucher’s and Rüdiger’s approach to the Copernican system they both embrace. For Rüdiger, the Copernican hypothesis is seen as a probable truth we can hold on to as long as we don’t obtain competing empirical sensiones and ideas, even if our globe should not really move around the sun. For Bucher though, it is a demonstrated truth that gains additional support by a machine that imitates the working of the world machine.