The same way I don't need to understand aerodynamics to know that I have no reason to believe that turtles might be capable of flight. I've never seen a turtle do anything that sits in the neighbourhood of the notion of "flight" in the network of concepts in my head. This type of argument doesn't work against the putative consciousness of foetal brains, since we have good reason to believe that at least brains at a certain stage of development are in fact conscious. To argue that this means we can only have an ethical problem with running dubious experiments on brains at that stage of development is rather like arguing that since you've only ever seen white swans fly, the supposition that black swans might fly too is not justified as such.
The same way I don't need to understand aerodynamics to know that I have no reason to believe that turtles might be capable of flight.
You don't need to know the underlying mechanics, but you do need to know what flight is.
You're saying we don't even know what consciousness is.
To argue that this means we can only have an ethical problem with running dubious experiments on brains at that stage of development
No one is arguing that. I am saying that if you claim to have a problem, you have to be more specific about what your problem is and what might co...
This seems significant:
http://www.theguardian.com/science/2015/aug/18/first-almost-fully-formed-human-brain-grown-in-lab-researchers-claim