Materialists argue that dualism of mind and brain is not possible because of causal closure — by which they mean that all physical effects have physical causes.
When sunlight is adequate, leaves are happy. On some days, though, there can be too much of a good thing.
The fact that nature is not predetermined in detail has been shown quite convincingly by the experimental confirmation of Bell’s theorem in quantum mechanics.
Imagine a chain hanging from the sky supporting a weight suspended in the air. Each link in the chain is a cause for the continued suspension of the links.
Around 50 BC Titus Lucretius Carus wrote a long treatise against finding purpose in nature.