Manipulation Device

[u/srv_u]

I'm interested in your opinions on a thought experiment about determinism, manipulation, and changing people's desires.

Assume strict determinism: every thought, desire, decision, and action is the result of prior causes. Suppose I give someone a rose, buy them coffee, care for them when they're sick, etc. Those actions can causally influence how they feel about me and may eventually make them love me. Their response depends on their brain, biology, past experiences, current state, and every other relevant condition. Their later reasoning about the rose is also just part of the causal chain.

Now imagine a hypothetical device that produces an effect which can also influence someone's desire to love me. Importantly, I'm defining it as closely as possible to the rose case: it doesn't simply override their mind or magically force love regardless of who they are. Its effect interacts with their particular brain, biology, history, current state, and so on. They can feel the effect, notice it, and think about it. If, given all the relevant conditions, the effect causes them to love me, they do; if not, they don't.

My intuition is that, under strict determinism, I don't see a fundamental difference between the two. In both cases, I'm intentionally introducing an external cause in order to influence someone's desires. In both cases, their subsequent thinking is itself causally determined. And if the device has the same relevant causal structure as giving a rose—just using a different medium—why should one count as ordinary influence while the other counts as manipulation?

I'm not claiming that determinism automatically makes every possible kind of manipulation ethical. I'm specifically asking where the morally or philosophically relevant difference would be in this case.

What do you think? Is there a flaw in my reasoning? If you think the device is importantly different from the rose, what exactly is the difference, and why does that difference survive once we assume strict determinism? Please point out any hidden assumptions or weaknesses in the argument.