"When we try to pick out anything by itself, we find it hitched to everything else in the universe." -- John Muir
When Descartes partitioned the world into the res extensa (material objects) and the res cogitans (mind), he treated the two domains quite differently. In chapter VI of Meditations and Principles (1644), he writes:
"... there is a vast difference between the mind and body, in respect that body, from its nature, is always divisible, and that mind is entirely indivisible."
The body he viewed as a machine, which could be understood by the interactions of its constituent parts. Hence, the dissection of material objects, in general, into their components -- that is, reductionism -- was seen as a viable approach to understanding the whole.
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